Glossary Of Terms
Disclaimer
This glossary explains many terms related to heart issues. Our aim is to help inform readers of the meanings and uses of various terms. The contents are not advice, and the BCPA and the author cannot accept any responsibility. The choices of what terms are included are somewhat arbitrary – including terms on prevention, diagnosis, symptoms, treatment, rehabilitation, and research.
For ease of English style, we have sometimes used 'you' to mean the patient or carer, as well as the reader.
Medical Records
You have a right of access to your health records. The Data Protection Act 1998 allows you to have access to information about you held by a hospital or doctor. You are entitled, upon making a written request, to be supplied with a copy of any personal data held about you. For information on how to apply and the charges contact the appropriate manager – eg of patient services at the hospital.
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1/7 = one day, or one day each week.
1/52 = one week or one week each year. 3/12 = 3 months. 12/12 = all of a year.
< means less than and not equal to.
> means greater than, ie more than and not equal to.
< and <= both mean less than or equal to.
> and >= both mean greater than or equal to.
| means or.
* sometimes means multiply.
Ablation is a general term with three meanings.
1 The surgical removal of an organ, structure, or a part of such. This can apply to any part of the body – it is not heart-related.
2 The melting or wearing away of an expendable part – eg of the heat shield of a spacecraft during reentry.
3 The wearing away of part of a rock or glacier.
See ablation for AF under Atrial Fibrillation.
Radiofrequency Ablation of Atrial Flutter is a treatment to correct an abnormal heart rhythm. Through a vein in the groin at the top of a patient's right leg and/or a vein under a collarbone, wires are passed to the heart. These are used to ablate, ie burn away, the exact pathway in the heart that is causing the atrial flutter.
Access to medical records. You have a right of access to your health records. The Data Protection Act 1998 allows you to have access to information about you held by a hospital or doctor. You are entitled, upon making a written request, to be supplied with a copy of any personal data held about you. For information on how to apply, and the charges, contact the appropriate manager – eg of patient services at the hospital.
ACE inhibitor stands for Angiotensin converting enzyme inhibitor.
AED stands for automatic external defibrillator.
Acetone is a chemical with formula CH3COCH3; a colourless, volatile, liquid; used in the manufacture of some other chemicals; and also used as a solvent & thinner for paints, varnishes and lacquers.
AICD stands for automatic implantable cardioverter defibrillator.
Acute Coronary Syndrome,ACS, is a general term for unstable angina with related conditions.
Addiction means compulsive use of a drug and/or continual craving, usually leading to physical and/or psychological dependence – eg for a particular drug, nicotine by smoking, or caffeine in coffee and/or tea.
Adjuvant is a drug that enhances the effect of another drug. Eg aluminium is added to some vaccines to increase the immune response, so increasing the protection.
Adrenocorticotrophin. See under Stress.
Adrenaline is a hormone produced in the medulla (innermost centre part) of the adrenal glands in response to stress. It increases the heart rate and blood pressure; and raises the levels of glucose and lipids. See Epinephrine and under Stress.
The two adrenal glands are at the anterior end of each kidney.
Adverse effect means an unwanted side effect. Adverse reaction means the same.
AED. See Automatic external defibrillator.
AICD See Automatic implantable cardioverter defibrillator.
Alkali. See alkali under protein.
Alcohol unit. An alcohol unit is roughly* the alcohol in half a pint of beer or lager, or roughly* a glass of wine, or roughly* a single measure of spirits. *Here 'roughly' means that some pub measures are more than one unit – particularly of wines and spirits, because the volumes of the measures and/or glasses have increased, and also because different alcoholic drinks differ in their alcohol content.
Men should not to have more than 21 alcohol units per week, and women not more than 14. Preferably have about 3 to 4 units per week.
A large amount of alcohol any evening may significantly raise your blood pressure the following day.
Some experts believe that for adults one glass of a chardonnay or of red wine every day or two – but not more alcohol than that – reduces the risk of coronary heart disease.
See also red wine under apple.
A research trial finished in 2004 compared various groups of people who drank different amounts of alcohol, and the analysis found the following to be statistically significant.
(a) Men who drink three or more units every day and/or are binge drinkers are more likely to have a stroke than non-drinkers.
(b) Men who are at lowest risk of stroke were men who drank one or two units three or four times per week. They had slightly lower risk both than non-drinkers and than those who drank one or two units of alcohol every day.
(c) Men with the lowest total risk for any or all three of CHD, strokes and diabetes taken together are those whose alcohol consumption was limited to one drink unit, or at most two, about every other day, with little benefit shown above three or four drinking days per week.
Although this research was only based on analysis of men, experts expect the patterns for women are likely to be similar. See also Stroke.
Another research trial in 2004 compared two groups of men and women aged from 30 to 74. One group drank 300 ml of red wine, which is just over one unit, daily for four weeks; and as a control group for comparisons the others drank red grape extract or water.
● In the red wine group the HDL of each person typically increased by 11% to 16% of its value at the start. No significant HDL difference was observed in the control group.
● In the red wine group the amount of fibrinogen of each person typically decreased by 8% to 15%. No significant fibrinogen difference was observed in the control group.
Other research trials have shown that moderate* red wine and/or white wine such as chardonnay is protective against CHD, but other forms of alcohol are not. However the explanations may lie in other factors such as differences in the lifestyles and habits of the people who prefer the different kinds of drinks. *The term moderate here implies about one unit per day or two, from three to seven units per week, but not more.
Excess alcoholic drinks every day gradually affect the liver, and once liver damage has happened it is not reversible.
Also beers and similar drinks contain energy – far more than drinks of wine with the same alcohol content. So drinking beers and similar drinks tends to lead to becoming overweight. Drinking wine instead is preferable as regards avoiding being overweight.
Alcohol – Hospital alcohol gel for rubbing on hands does not prevent C diff. But it does prevent MRSA.
Allergy. An allergy is when a substance triggers an undesirable or over-reaction in the immune system. An allergic reaction means the same, particularly when the reaction does not occur on the first exposure but appears on a later one. See ambulance for when to call an ambulance.
The immune system protects the body by eliminating foreign substances that it does not recognize – eg microorganisms such as bacteria or viruses. It produces antibodies.
When the body first gets a new foreign substance, one kind of white blood cell – called lymphocytes – produces the antibodies. These attach themselves to a second kind of white blood cell – called mast cells.
If the body gets the same foreign substance again, the mast cells release chemicals called mediators, eg histamine. This can produce a rash, swelling, narrowing of airways, and/or a drop in blood pressure. The antibodies and mediators protect against infections; but unfortunately may be triggered inappropriately – which is then an allergy.
When it is impossible for the patient to avoid the substance triggering the allergy, treatment is usually by antihistamines and/or corticosteroids, and/or drugs that minimize the symptoms.
Alphablockers block nerve signals that would trigger narrowing of blood vessels. Several alphablockers are available.
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Doxazosin |
Brand name Cardura, Doxadura |
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Indoramin |
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Prazosin |
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Terazosin |
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Ambulance. Some people advise that in general one should call an ambulance without delay if someone has any of the following life-threatening conditions.
● Not breathing/cardiac arrest
● Severe chest pain – such as unexpectedly, or a heart attack, or angina that continues after initial treatment
● Difficulty in breathing
● Loss of consciousness
● Severe loss of blood
● Severe burns and scalds
● Choking
● Fitting/convulsions
● Drowning, and/or
● Severe allergic reactions.
At a road traffic accident, as soon as you know how many casualties and the severity of their injuries – eg whether conscious or unconscious, and whether likely to be stretcher cases – get someone to phone for an ambulance and tell them a brief description of the injuries.
If the patient's condition does not fall into the list above it may still be that an ambulance is required. Such patients are classified as having a serious condition but not immediately life-threatening.
A good example is a lower limb fracture. This is a stretcher case and definitely requires an ambulance. But the call would not be classified as immediately life-threatening unless the patient was for example also unconscious or bleeding severely. So the ambulance service need a brief but accurate description of the condition of the patient so they can classify it correctly.
This is important for two reasons.
● Resources are allocated to calls based on how serious they are rather than when the call was received. So if an ambulance is on its way to a broken leg but a chest pain call comes in nearby it will be sent to the chest pain call with another vehicle from further away being sent to the broken leg.
● If an ambulance is more than 8 minutes away then whenever possible Community Responders or off-duty ambulance staff will be deployed to 'immediately life-threatening calls' but not normally to other calls.
The rule for an Automatic external defibrillator (for a lay person) is that it should only be attached to a patient who is both not responding and not breathing. Lay people should not check for a pulse – it will waste time and may be incorrect. Provided the patient is both unresponsive and not breathing the AED can be relied upon to deliver a shock only if necessary.
Paramedics have AED equipment in ambulances to restart a patient's heart. They have oxygen, and have facilities to insert a cannula into a vein and administer appropriate injections. They also have ECG monitoring and recording equipment.
These facilities have improved over recent decades, and increased the chance of survival and recovery from heart attacks and other conditions. Because a first aider generally does not have these facilities, an ambulance should be called as soon as possible.
Before the provision of any AEDs, sadly only 2-3% of UK cardiac arrest casualties survived. But AEDs and better first aid training have increased the survival rate.
Anaemia is a deficiency of red blood cells and/or in their haemoglobin content. Haemoglobin combines reversibly with oxygen and so is important for transporting oxygen in the blood to tissues. Symptoms of anaemia include breathlessness – short of breath, pallid complexion, fatigue, and general lack of energy. These are all caused by the lungs, heart, and/or blood circulation not supplying enough oxygen.
Vitamin B12 is needed to avoid anaemia. Folic acid, iron, potassium, and cobalt are also needed.
Pernicious anaemia symptoms are a feeling of weakness and eg: lesions of the spinal cord, sore tongue, numbness in arms and legs, and/or diarrhoea – all caused by the deficiency of red blood cells and of haemoglobin, and hence not enough oxygen being carried.
Anaesthetic. An anaesthetic is a drug that produces either a local loss of sensations of touch or pain over a small part of the body, or temporary unconsciousness – such as for an operation or some other procedure that would otherwise be painful.
An anaesthetist is a doctor specializing in anaesthetics, which is the science of such drugs.
Analgesia is the inability to feel pain. It also means relieving pain by drugs.
Analgesic. An analgesic is a chemical that reduces pain – a painkiller. Pain is a symptom, not a disease. Longterm relief therefore needs treatment of the underlying cause. If the underlying cause cannot be cured, longterm analgesic treatment, eg by drugs, may be needed.
Nerve endings detect damage to body tissues from disease or injury, and send signals to the brain. The brain's interpretation of these signals may depend on the patient's psychological state, eg may be worse with anxiety or fear. Support and reassuring explanation may help the patient to bear the pain and/or may relieve it.
Analgesics divide into opioids – the strongest pain relievers, and non-opioids.
Non-opioids = NSAIDs and non-NSAIDs. The non-opioids divide into Non steroidal anti-inflammatory drugs, NSAIDs, eg aspirin; and non-NSAIDs eg paracetamol.
NSAIDs relieve pain, inflammation, and/or swelling – usually of joints and/or muscles and reduce fever.
Non-opioids block the production of prostaglandins, so the nerve endings that would send pain messages to the brain are prevented from being stimulated. Thus eg paracetamol relieves pain and inflammation.
Pain-relief products named Co- – eg Co-codamol, Co-codaprin, Co-proxamol – contain both an opioid and a non-opioid; the non-opioid part may be either paracetamol or another NSAID. But codeine is just an opioid analgesic.
Analysis, analysing means examining in detail, breaking down into parts or components, finding out about each component, and understanding how the parts work together.
Anaphylaxis is a severe allergic reaction. The symptoms are swelling of the throat or tongue, hives, and/or trouble breathing. When it strikes, life is at risk. So time is critical. It may cause shock.
Many people carry a lifesaving device that gives an easy-to-use injection of Epinephrine. See also under shock for symptoms and treatment of shock.
Aneurysm. See Aortic aneurysm.
Angina See separate factsheet on angina.
Angina is a chest pain – an uncomfortable feeling in the chest that is usually brought on by exercise or emotional upset. For some people it is hardly a pain at all, but for others it can be severe. The commonest complaint is of a heaviness or tightness in the middle of the chest. The pain may spread to the left shoulder, left arm and hand; neck, throat, jaw, back and/or stomach. The patient may be temporarily short of breath, and/or feel weak and/or anxious. Also called angina pectoris.
Angina is a built-in warning device, telling you that your heart is trying to do too much and that you must take it easier.
Angina is most often caused by the gradual narrowing of the arteries of the heart by materials being deposited in their walls. Over many years, these deposits increase until they reach a size where they actually restrict the flow of blood through the arteries.
When a patient's body is at rest and the heart is beating at its normal resting rate, sufficient blood passes into the heart muscle to nourish it. Under exercise or strong emotion the heart is put under strain by being made to beat faster and a point is reached when the flow of blood and the oxygen it carries is insufficient to meet the increased demand of the heart muscle. Those muscles are starved of oxygen so cannot function properly, and this produces pain.
Anyone who unexpectedly gets such pain or symptoms should rest immediately and call an ambulance if either:
● it is not stable angina; or
● if both it is stable angina that the patient has had before and understands, and it does not respond within a few minutes to rest.
Angiography, angiogram. Cardiologists often recommend an angiogram for patients with angina. Under local anaesthetic, a fine catheter tube is introduced into a femoral artery in the groin and passed along the body’s arteries to the Coronary arteries. A dye is injected to give an X-ray picture of the blood flow and arteries. This will show both where and how much the coronary arteries are narrowed.
Nowadays the whole procedure can be done in a day. The results are stored in a computer system without the need for Xray film. The surgeon and staff can control the frequency of the images – eg having far fewer images per second than used to be needed with Xray film, and the Xray dose is much lower than ten or 20 years ago. The process takes about 30 to 45 minutes. With improved methods of treating the femoral artery wound – eg Angio-seal®, the patient typically needs only a couple of hours afterwards in the hospital.
Angioplasty means passing a catheter along an artery to the heart. The angioplasty entry is often made into the femoral artery at the patient’s groin, or sometimes in the arm or wrist. A local anaesthetic is usual.
An angioplasty catheter is a long, flexible, slender or very-fine hair-like hollow guide wire that can be fed along an artery – eg the femoral artery. It is used either to help place a balloon or stent in position, or to inject a dye. The cardiologist guides the wire by viewing an X-ray picture. The wire may be made so its natural shape near the end is a slight curve, so by rotating it when an artery junction is reached, it can be guided into the correct route. See Balloon angioplasty, Cardiac catheterisation, and Coronary angioplasty and stent insertion.
Angio-Seal® is a vascular closure device fitted to a femoral artery wound. Its parts are absorbed within 90 days. It has an anchor that goes inside the artery hole, a suture that comes towards the skin, and a collagen sponge around the suture that is pushed to the outside of the artery to block the hole. There is no latex and it is MRI compatible.
Angiotensin converting enzyme inhibitors, ACE inhibitors. ACE inhibitors are drugs used to reduce high blood pressure and/or to help the heart to pump more efficiently and effectively. They act on enzymes and dilate blood vessels throughout the body, thus reducing the blood pressure by lowering the pressure against which the heart has to pump. ACE inhibitors are beneficial where the heart failure is due to abnormalities in how well the left ventricle pumps. They also prolong life. Many different ACE inhibitors are available.
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● Captopril |
Brand name Capoten |
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● Enalapril |
Brand name Innovace |
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● Lisinopril |
Brand names Carace, Zestril |
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● Ramipril |
Brand name Titrace |
If you are taking the dose once a day, it is best to take it in the morning. If you are taking more than one dose per day, then space them out evenly through the day.
When you first start taking ACE inhibitors or if your doctor increases the dose, you may experience a dizzy or faint feeling until your body adjusts to the dose. This should soon pass if you sit or lie down for a while. However, if this happens you should inform your doctor.
Some ACE inhibitors, eg perindopril, have anti-blood-clotting properties and restore the smooth lining of the arteries, stopping the build-up of fats in the artery walls.
A new drug, valsartan, was trialed internationally about 2003 – involving 15,000 patients in 54 hospitals. It was found to be as effective as other ACE inhibitors in reducing the risk of second or third heart attacks, but without giving patients a dry cough. Previously there was nothing to give to such patients. Brand name Diovan. It is an angiotensin II blocker, and is used to treat hypertension. It may also be used after a heart attack to reduce the risk of further complications.
Side effects of ACE inhibitors are relatively rare. They include dizziness, headache, fatigue, diarrhoea, muscle or joint pains, dry cough (see above) and rash or skin itch. If you experience any side effects, contact your doctor.
Angiotensin II blocker. Angiotensin II is a powerful hormone that constricts blood vessels. An Angiotensin II blocker blocks that action, so relaxes the blood vessels. This makes the arteries and veins slightly larger calibre, reducing the heart workload and lowering blood pressure.
Antagonist means having the opposite effect, eg a drug that blocks something.
Anterior means situated at or towards the front of the body. Opposite of posterior.
Antibiotic means a substance that kills particular bacteria or fungi.
Antibodies are chemicals produced and used by the lymphocytes (a particular kind of white blood cell in the) immune system to help the body to overcome infection, disease, allergy, or unwanted foreign substances – viruses and bacteria. They are blood proteins. Anti- means against.
Anticoagulant. Anticoagulants are drugs to reduce or prevent blood coagulating or clotting in blood vessels, or to prevent a thrombosis or embolus causing trouble in the bloodstream.
Heparin is an anticoagulant that is used to prevent blood clots forming, and/or to prevent existing clots getting bigger or breaking and producing an embolus.
Warfarin is an anticoagulant drug, and is named after Wisconsin Alumni Research Foundation and Coumarin. Coumarin is an anticoagulant. Warfarin is usually taken by mouth.
Antihistamine. See Antihistamines under Histamine, Corticosteroids.
Antihypertensive. An antihypertensive is a chemical that reduces high blood pressure, and may be taken longterm to maintain lower blood pressure.
Antihypertensive drugs work in various ways – acting on different parts of the body to reduce blood pressure.
Alphablockers block nerve signals that would trigger narrowing of blood vessels.
Centrally- acting antihypertensives affect the brain mechanism that controls blood vessel size.
Betablockers that are heart related reduce the force / pressure at each heartbeat.
Diuretics cause the kidneys to reduce blood volume.
ACE inhibitors, Angiotensin converting enzyme inhibitors, act on enzymes and dilate blood vessels.
Vasodilators and calcium channel blockers act on the muscles of the walls of arteries to prevent narrowing.
Antioxidant. An antioxidant is a chemical that protects against damage by free radicals. Equivalently, an antioxidant retards deterioration by oxidation – especially of fats, oils, foods, petroleum products, and rubber.
A free radical is an atom or group of atoms containing at least one unpaired electron and existing for a brief period of time before reacting to produce a stable molecule.
Vitamin E is an antioxidant.
Antiperspirant is a substance applied to the skin to reduce sweating. They reduce the processes in sweat glands and/or block ducts that carry the sweat to the skin surface.
Antiplatelet drugs help prevent platelets sticking together to form blood clots. Usually they are taken regularly. Such drugs are also given after heart surgery to prevent clots forming. Aspirin is the most widely used antiplatelet drug. See International Normalized Ratio.
Antipyretic is a drug that reduces fever – eg paracetamol under analgesic, aspirin.
Aorta is the large artery that emerges from the heart’s left ventricle, and carries blood towards the rest of the body.
Aortic aneurysm is a sac and/or dilation at some place in the aorta where the aorta artery wall may be weakened or damaged.
Aortic stenosis. Stenosis of the aorta.
Aortic valve is the valve between the left ventricle and the aorta, which allows blood to flow out to the rest of the body but not backwards. See Valve.
An apple a day. Flavonoids in the diet lower heart disease risk. Quercetin and epicatechin are the major flavonoids in our diet – their main sources being red wine, cocoa, onions, tea, and (particularly) apples – ROTA.
There is increasing evidence that diets rich in fruits and vegetables are associated with a reduced risk of chronic disease such as cardiovascular disease. This may be due to the abundance of phytochemicals (plant chemicals) known as polyphenols that occur in these foods. The Institute of Food Research staff are researching protective effects of a particular class of polyphenols occurring naturally in apples against vascular disease.
Arrhythmia means an abnormal rhythm of the heart. This may be from a birth defect, coronary heart disease, other heart disorders, overactive thyroid gland, caffeine, and/or drugs for Parkinsonism or incontinence. See Atrial fibrillation, Supraventricular tachycardia and Arrhythmogenic right ventricular cardiomyopathy under cardiomyopathy.
Artery. An artery is a blood vessel in which blood flows from the heart to part of the rest of the body. The main artery from the lower left ventricle of the heart is the aorta. The tubes from the lower right of the heart to the lungs are also called arteries. Compare Vein. See Coronary arteries, Coronary artery bypass graft, Internal mammary artery.
The risk factors that cause narrowing and/or blockage of the arteries are:
● smoking
● being overweight
● lack of exercise
● history of heart disease in the family
● if you are male
● if you are diabetic
● if you suffer with stress.
These risk factors do not make it certain that a person will have heart trouble. Some people develop angina without having any of these risk factors.
Arthritis is an inflammation of joints, causing pain and stiffness. See Arthritis under NSAIDs.
Artificial pacemaker. An artificial pacemaker is an electronic device fitted under the chest skin, and that can generate a pulse to control heart rate. It is usually fitted to patients that have a slow heartbeat. Compare Implantable cardio-defibrillator.
Aspirin in low doses helps to prevent blood clots and to reduce the viscosity of a patient's blood, thus making it flow better, and thus reducing the need for higher blood pressure to pump it round the body – see Antiplatelet. This decreases the risk of a heart attack or stroke. It is important to take the correct dose, usually 75-150 mg daily, as higher doses will not have the desired effect on the blood or heart.
Aspirin is a non-steroidal anti-inflammatory drug(NSAID). Aspirin also reduces inflammation, and in the correct low dosage prevents abnormal blood clotting, but normal doses irritate the stomach lining. Soluble or dispersible aspirin in water is absorbed into the bloodstream faster than tablets would be, but still irritates the stomach lining.
Aspirin has been used as a pain reliever since about 1920, and is present in many medicines for colds, flu, headaches, and other pains. Aspirin tablets as such generally have higher doses, eg 300 mg.
Higher doses than 75-150 mg may injure the stomach lining, and cause stomach ulcers* and intestinal bleeding. This has been known since the 1950s or perhaps earlier. Thus generally, people should not take aspirin as a pain reliever. Preferably take paracetamol or ibuprofen or whatever a doctor recommends. Aspirin can also trigger asthma attacks. As regards stomach ulcers, aspirin is an NSAID: See under NSAID.
Aspirin as a drug. A daily low dose of 75-150 mg of aspirin is to reduce the stickiness of the patient's blood, thus decreasing the chance of a heart attack or stroke. Aspirin should be taken at the same time every day. Take aspirin with or immediately after food as this reduces the risk of stomach irritation. Most people take soluble or dispersible aspirin, which are white tablets that should be completely dispersed in a small glass of water.
Aspirin side effects are rare, as the dose of aspirin is very low. Occasionally aspirin may cause stomach upsets or indigestion pain, but this should be prevented if the dose is taken with food or milk. If you, the patient, still suffer stomach pains then you should contact your doctor. Aspirin occasionally causes wheeziness due to an allergic reaction – if you experience this you should contact your doctor.
If you require medication as a painkiller, you should take one that does not contain any aspirin, such as paracetamol.
Many cold remedies may also contain aspirin as well as other ingredients and these remedies should be avoided to keep the aspirin dosage correct. Ask your pharmacist for advice if you are not sure. It is helpful to keep a list of all the medication you are currently taking and their dosages with you whenever you visit a doctor or hospital.
Aspirin Reye's syndrome. Experts advise that one should never give aspirin to anyone under 16, because of the risk of a rare but sometimes-fatal liver and brain disorder called Reye's syndrome.
Assertion. Assertion has two meanings. In ordinary usage it refers to a positive statement – perhaps made without any evidence or justification.
In science and medical research, an assertion is a proposition that may be true or false, and carefully worded so that its assumptions and meaning are clear. Usually the intention is to state exactly what is to be tested, eg a particular null hypothesis, as explained under Statistically significant.
Atheroma is the term for the fatty material that builds up on the inside walls of arteries, particularly the coronary arteries. This usually leads to angina pain. Similar build-up in arteries supplying the brain may lead to a stroke.
Atherosclerosis means the fatty deposits on artery walls due to the build-up of cholesterol and other cells; with related thickening of the walls, so the narrowing reduces the blood flow.
The term also means the narrowing and thickening of the arteries. Where this occurs in coronary arteries, it reduces the blood and oxygen reaching the heart muscle, so less blood can be pumped around.
Atherosclerosis is the leading cause of cardiovascular disease (CVD) mortality, and is an inflammatory disease.
Atherothrombosis means plaque tearing. The fragments may lead to blood clots forming and thus the furring up or blocking of arteries.
Atrial fibrillation is a very common abnormality of heart rhythm – about 10% of people over the age of 70 have it. When this occurs, the top chambers of the heart – the atria – beat in a chaotic fashion, called fibrillation. It may be treated with drugs.
See separate factsheet on Atrial Fibrillation.
Atrioventricular node. The A-v node is the conduction pathway between the upper and lower chambers of the heart.
Atrium. The right atrium RA is the upper right chamber of the heart, where blood from the body enters before flowing to the right ventricle. Similarly the left atrium LA is the upper left chamber, where oxygenated blood from the lungs enters and then flows to the left ventricle and thus to the rest of the body. The plural is Atria.
Automatic external defibrillator, AED. An AED is a machine that gives a controlled electric shock to restart the patient's heart. Ambulances carry an AED. Never give such an electric shock to a patient that has a pulse.
For a reasonable chance of survival this is needed within 8-10 minutes of a patient's collapse, hence the urgency to call 999.
The rule for an Automatic external defibrillator (for a lay person) is that it should only be attached to a patient who is both not responding and not breathing. Lay people should not check for a pulse – it will waste time and may be incorrect. Provided the patient is both unresponsive and not breathing the AED can be relied upon to deliver a shock only if necessary.
See also ambulance.
Public Access Defibrillators (PAD) are available eg in shopping centres, entertainment venues, and other public places. Once opened, the machine gives instructions through its computer and loudspeaker.
Automatic implantable cardioverter defibrillator, AICD. An AICD is a device implanted to monitor the heart and that will if needed automatically deliver a controlled electric shock to restart the heart.
Average. The word 'average' means whichever is appropriate of three different calculations on a set of values. Usually the average is taken to be the mean unless the context implies otherwise.
The mean is the total divided by how many. Eg the set of five values 7, 7, 12, 12, 12 has mean 10 = (7+7+12+12+12)/5. Also see Standard deviation.
The mode is the value that occurs most. Eg the mode of 1, 1, 2, 14, and 15 is 1. This is useful where some consequence depends on the commonest case.
The median is the central value of an odd number of values, or is the mean of the central two if there are an even number. Eg the median of 1, 3, 5, 16, and 17 is 5; and of 1, 4, 6, and 17 is also 5. Essentially, half the values are above it, and half are below it.
AVPU see consciousness.
AVR = Aortic valve replacement. See Valve surgery.
Balanced diet. See Balanced diet under diet.
Balloon angioplasty. This is a procedure where an angioplasty catheter is used to place a tiny balloon at a blocked or partially blocked place in an artery. This is then inflated to about 3 mm diameter and it flattens the fatty tissue that was blocking the artery against the artery wall. Usually, a stent is inserted to keep the artery open. The balloon is deflated, and the catheter is withdrawn.
Basal metabolic rate. See basal metabolic rate under Metabolism.
bd (= bpd) = twice per day. Also see od = once a day, tds = three times, qds = four times. om = every morning.
Beating heart transplant. On 22nd May 2006 a team at Papworth hospital performed the first ‘beating’ heart transplant in the UK. The recipient - a 58-year old man - was two weeks later doing extremely well and had already left hospital.
A donor heart will deteriorate without a blood supply outside the body and the current method of preserving its function is a high dose of potassium to stop it beating, and then cooling to maintain it during transport. Unfortunately despite the above measures the heart slowly deteriorates and there is a safe time limit of about 5 hours between removal from the donor and implantation to the recipient.
In the new system, developed by TransMedics in the USA, the heart is transported in an Organ Care System with conditions as close as possible to the human body; it has warm oxygenated, nutrient-rich blood flowing through it and thus continues to beat. The new technique should mean that the heart is in better condition at the time of the transplant. The organ care system may also allow the time interval before transplantation to be extended and possibly allow drug treatment to be used to improve hearts prior to transplantation. The latter will increase the number of donor hearts that can be used for transplantation, which would be a major benefit.
Beats per minute = Heart rate.
Betablocker = beta-adrenergic blocker. Betablockers slow the heartbeat, and are used to: relieve angina, reduce high blood pressure, reduce the risk of a further heart attack, and/or regulate the heart rhythm. Some betablockers also relax the blood vessels.
They interrupt the transmission of stimuli through the body's beta receptors. Thus they nullify the stimulating action of norepinephrine (= noradrenaline), which is the main fight-or-flight hormone. The beta receptors in different parts of the body produce a variety of benefits and/or side effects – the benefits or otherwise depend on what conditions and/or diseases the patient has. The main effects of beta blockers follow.
● Heart rate is slowed and the force / pressure in the outflowing blood at each heartbeat is reduced – the reduced heart workload helps prevent angina and/or abnormal heart rhythms. Unfortunately this may increase the risk of heart failure.
● Blood pressure is lowered since the heart rate and the heart's force / pressure is reduced.
● Blood vessels are narrowed, which may cause the hands or feet to feel cold from reduced blood flow.
● Overactivity of the thyroid gland is reduced – so muscles may tremor from that or from anxiety.
● Narrowing of airways to the lungs may cause breathlessness.
● Dilating blood vessels surrounding the brain is inhibited (= prevented).
In summary they are effective because they slow the heart rate, reduce the workload of the heart, and lower the blood pressure.
Betablockers are prescribed for a number of conditions.
● Relieve angina chest pain, as they reduce the frequency and/or severity of angina.
● Reduce high blood pressure
● Reduce the risk of a further heart attack
● Regulate the heart rhythm.
Many different betablockers are available. Some mainly affect the heart; others are not aimed at the heart. The following mainly aim at the heart, eg to stop the heart from beating too fast.
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Acebutolol |
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Atenolol |
brand names Antipressan, Atenix, Tenormin |
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Betaxolol |
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Bisoprolol |
brand names Bipranix, Cardicor, Emcor, Monocor, Soloc, Vivacor |
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Celiprolol |
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Metoprolol |
brand names Betaloc, Lopresor |
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Nebrivolol |
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The following are mainly not aimed at the heart.
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Carvediol |
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Labetalol |
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Nadolol |
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Oxprenolol |
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Pindolol |
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Propranolol |
brand name Inderal |
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Timolol |
brand names Betim, Glau-opt, Nyogel, Timoptol |
If you, the patient, are taking the dose once a day it is best to take it in the morning. If you are taking more than one dose a day, then space them out evenly through the day. The tablets, particularly the slow-release SR variety, should be swallowed whole with a glass of water and never crushed or chewed.
It is important never to stop taking betablockers suddenly without consulting your doctor.
Betablockers side effects are relatively rare. Occasionally people suffer with cold hands and feet. Make sure you keep warm in the cold. You may feel tired when you first start taking betablockers. This usually passes within a few days, as your body adjusts to a slower pulse rate. A minority of people may suffer wheeziness or breathlessness when taking betablockers. People with asthma should not normally take Betablockers. Very rarely, men may suffer from impotence whilst taking betablockers. If you notice any of the above side effects, you should contact your doctor.
Bile is a greenish to golden brown liquid produced by the liver and stored in the gall bladder. During digestion of food it is released into small intestine via the bile duct to aid digestion. It is also discharged into the duodenum where it helps the emulsifying of and absorption of fats. See Cholesterol, lipid-lowering drugs.
Bilirubin. See under jaundice.
The Biotechnology and Biological Sciences Research Council, BBSRC, is the UK funding agency for research in the life sciences. Sponsored by the government, with a budget of £370 million in 2007, it supports industrial stakeholders in the agricultural, food, chemical, healthcare, and pharmaceutical sectors. See also Institute of Food Research.
Blocker. See antagonist.
Blood contains red cells, white cells, plasma, and platelets and other agents that are active in the clotting of blood. Plasma is the clear or yellowish fluid in which corpuscles and cells are suspended; including water, dissolved proteins, salts, sugars, fats, minerals, and vitamins. Red cells have haemoglobin for carrying oxygen. Antibodies for various diseases are proteins in the blood that render the toxins harmless.
Blood analysis measures the amounts of particular substances in a blood sample in a blood test.
The equipment is called a blood analyser. In 2004 the BCPA bought seven for Papworth Hospital, costing over £15,000. Each could measure the clotting properties, INR, and other variables in a few minutes from a drop on a slide. The previous equipment needed a tube full of blood and took hours.
Blood cholesterol test. A blood cholesterol test measures the amount of cholesterol and other fatty substances in a blood sample.
Blood clot. A blood clot is an unwanted lump of blood platelets creating a blockage in an artery or vein. A part of such a clot may break away – called an embolus, and if it flows to some other place it may cause further problems there. Deep vein thrombosis means a blood clot in a leg.
Blood pressure, BP, measures the systolic (highest) and diastolic (lowest) pressure during each heartbeat. For high blood pressure see hypertension. It is normal for blood pressure to rise with exercise, stress, and exertion.
Systolic is the maximum blood pressure during each heartbeat, eg the 130 of 130/80, measured in mm of mercury (Hg).
Diastolic is the minimum blood pressure during each heartbeat, ie the 80 of 130/80.
Blood test. A blood test is an analysis of a small sample of blood to measure the amounts of various chemicals and/or trace elements (see under Minerals) in the blood. Eg patients with unknown cholesterol, or with deep vein thrombosis, or taking Warfarin, are tested to determine the amounts of particular chemicals so that appropriate treatment may be given. The Glucose level is measured to check for diabetes. See also blood analysis, Troponins.
Body mass index, BMI, is the weight in kilograms divided by the square of the person's height in metres. Eg weight 75 kg and height 1.73 m gives 75/(1.73*1.73) equals 25.
Excluding people training for sports or ill the following are the relevant ranges. But for all these terms in detail it also depends on whether the person has a small, medium or large frame, and whether they are training for a sport.
For most adults a BMI between 20 and 25 is normal BMI¸ ie healthy and good.
● Under either 18.5 or 20 is normally regarded as underweight
● 25 to under 30 is overweight
● Over 30 is obese. See Obesity eg for risks.
Some people think Waist-to-hip ratio is a better measure.
Body salts are minerals present in body fluids such as blood, urine, sweat, or within cells.
Bones. The human body has 208 bones. The arms, wrists, & hands have 60. The legs, ankles, & feet have 60. The backbone has 26 vertebrae; there are 12 vertebral ribs each side, (a few people have 11 and are missing the lowest rib on each side). The skull has 22 bones. The ears have three each, and the throat has one. The collar & shoulder blades have four, the sternum (breastbone) has three, & the pelvic girdle has two.
The bones give rigidity, support, and shape to the body – including the ability of joints to move with muscles attached at appropriate places. They also give protection to certain parts – eg the skull & ribs protect. The inside of a bone is hollow and holds the systems that make blood cells and also make calcium. Bones are 33% water.
When they start growing they are solid, developing the hollow centres later. They also have the ability to repair themselves eg after a fracture – even a complete fracture broken right through. At a fracture the blood vessels also are damaged, so blood escapes as internal bleeding, and this blood clots into a hard mass to help the healing processes.
Bones can have various diseases. Congenital = hereditary diseases are rare and usually not curable, eg dwarfism, deformities. Biochemically caused bone diseases are where the body's functions have not worked properly to control the bones, eg rickets, weak bones. Bones can be infected by bacteria, eg osteomyelitis. They can also have tumours, eg a lump on the skull; and malignant growth such as cancer spreading from somewhere else. Osteoarthritis and rheumatoid arthritis first affect the lining of joints and the cartilage space between bones, and then affect the bones themselves.
BP stands for blood pressure.
Brachial means of the arm. Brachium means the arm, brachia being the plural.
Bradycardia is an abnormally slow heart rate, usually below 60 beats per minute. Compare Tachycardia.
Brand name = trade name = name for a particular product manufactured and marketed by a commercial company – a name chosen by the manufacturer. Contrast with generic name.
The different brands each contain the same generic substance. The differences between the brands may be slight – eg rate of absorption, convenience, and digestibility.
A particular drug may be available in generic form, in one or more brand forms, or both.
Some brand named products contain more than one, ie several, generic drugs.
Generic names are normally not spelt with an initial capital; but brand names normally have an initial capital.
Breastbone means the same as sternum.
Breathing. Being breathless, short of breath, may indicate a heart-related condition – eg angina; or perhaps anaemia. There are other possibilities.
See ambulance for when to call an ambulance.
Breathlessness can be caused by some heart- related condition that affects the flows of blood round the body and/or to and/or from the lungs.
British Heart Foundation, BHF, is a registered charity that plays a leading role in the fight against heart and circulatory diseases. It sponsors research and has produced many booklets. The BCPA and the BHF co-operate.
Tel 020 7935 0185, Website www.bhf.org.uk
British Heart Foundation National Centre for Physical Activity and Health, BHFNC, is at Loughborough.
They found that 37% of CHD deaths are related to inactivity; as compared to only 19% of CHD deaths being related to smoking.
See BHFNC under Exercise.
Bruce cycle. See Bruce Treadmill Test under Exercise stress test.
CABG stands for Coronary artery bypass graft. Pronounced 'cabbage'.
Calcium channel blockers are drugs used to relieve angina, reduce high blood pressure, and/or slow the heart rate. They act on the muscles of the walls of arteries to prevent narrowing. See Antihypertensive. They are prescribed for various conditions.
● Relieve angina
● Reduce high blood pressure
● Slow the heart rate.
Several calcium channel blockers are available.
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Amlodipine |
brand name Istin |
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Diltiazem |
brand names Adizem, Tildiem |
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Felodipine |
brand names Cardioplen, Felotens, Keloc, Neloc, Plendil, Vascalpha |
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Nicardipine |
brand name Cardene |
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Nifedipine |
brand names Adalat, Coracten, Nifensar |
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Verapamil |
brand names Cordilox, Securon, Univer |
These differ in their possible sites of action and their side effects. It is very important never to stop taking a calcium channel blocker without consulting your doctor.
Side effects of Calcium Channel Blockers. Occasionally people suffer with headaches and facial flushing, which usually stops after a few days as the body adjusts to the medicine. Those taking Verapamil may suffer constipation. Calcium Channel Blockers may cause dizziness. Again this should pass as your body adjusts to them. If you notice any side effects, you should contact your doctor, so that he or she may change your medication if these side effects become intolerable.
Calibre. The calibre of an artery is its internal diameter. Where there is plaque the partial blockage effectively reduces the calibre.
Calorie. A calorie is a unit of quantity of heat or energy. For measuring the amount of energy in foods, people use kilocalories, kcal, which is 1000 calories, which should be written Calories with a capital C to indicate kilocalories. People typically need 1800 to 2500 kcal per day. They use about 75 to 80 kcal per hour when resting in bed; and 80 to 90 when sitting and not doing any significant physical activity. During exercise the rate may double.
A Joule is a measure of heat or energy, being one Watt for one second. The conversion is 4.2 Joules per calorie, or 4.2 kJ per kcal. A slice of bread gives about 300 to 350 kJ, ie 70 to 80 kcal.
Campylobacter is the UK's commonest form of food poisoning – 42,226 cases and about 70 deaths in 2006. The true number of cases may be higher as many people might not go to see their GP. In vulnerable groups it may cause other complications. Some chicken flocks are carriers, leading to food poisoning.
Capillaries are the tiniest thin-walled blood vessels that arteries divide into, and where oxygen and other nutrients in the blood pass to muscles and other tissues.
Carbohydrates are an important source of energy as food. They are organic compounds containing carbon, hydrogen, and oxygen, usually with the hydrogen and oxygen in about the same ratio as in water. They include sugars – such as sucrose; and polysaccharides – such as cellulose, glycogen, starch, and various forms of glucose including dextrose. See also under Sugar, Diet, and Glycaemic Index.
Carcinoma. A carcinoma is a malignant tumour, or another name for a malignant cancer.
Cardiac means relating to the heart. A cardiac patient has a heart disorder; and a cardiac drug is one that stimulates heart muscles.
Cardiac arrest means the heart has suddenly stopped beating. Cardiopulmonary arrest means the same.
There is no pulse or breathing. The commonest cause is a chaotic electrical pattern caused by a ventricle or heart muscles being damaged or starved of oxygen. Causes include heart attack, severe blood loss, suffocation, electric shock, anaphylactic shock, drug overdose, and hypothermia.
Treatment: See ambulance for when to call an ambulance. CPR and resuscitation, defibrillation.
Cardiac catheterisation is a procedure where a catheter is passed along arteries to reach a particular coronary artery, and an X-ray video is recorded while a harmless dye is injected, causing the blood flow during each heartbeat to show on the X-ray. This helps detailed diagnosis, pinpointing the sites of blockages, and assessing the seriousness.
Cardiac ultrasound See Echocardiogram.
Cardiology is the branch of medicine of the heart and its diseases.
Cardiomyopathy has two related meanings. Firstly, it means the cause of the patient’s heart damage, which sometimes is initially not clear.
Secondly, cardiomyopathy is a heart-muscle disease that makes heart muscle flabby and weak. The heart then becomes bigger as the heart muscle wall expands under the strain. The cause is not understood.
Dilated cardiomyopathy means the heart is enlarged – and pumps less strongly. This means enlarged chambers.
Hypertrophic cardiomyopathy is heart muscle being thicker than normal. In some patients the muscle becomes thicker and can partially block the flow of blood out of the left ventricle to the rest of the body.
Restrictive cardiomyopathy is a heart-muscle disorder where the walls of the ventricles become stiff, but not necessarily thickened, so they resist normal filling with blood. The heart muscle is stiff and doesn’t relax properly.
Arrhythmogenic right ventricular cardiomyopathy is an inherited heart-muscle disorder where damaged heart muscle is gradually replaced by scar tissue and fat.
Cardiomyopathy Association CMA. The Cardiomyopathy Association, Registered Charity 803262, helps people and their families affected by the heart muscle condition cardiomyopathy.
The CMA provide support and easy-to-understand information on the different types of cardiomyopathy. The Cardiomyopathy Association meets a need unfulfilled by any other organisation and is supported solely by public donation.
As well as information on their website www.cardiomyopathy.org (This is not a link), they provide booklets on the three main types of cardiomyopathy – hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy. They also have videos and CD ROMs on hypertrophic and dilated cardiomyopathy. They have support groups around the UK where members can learn more about the condition and share experiences. They have a network of people affected by the condition who can offer one-to-one support on the telephone. They hold regional information days around the country at which cardiologists experienced in dealing with cardiomyopathy give presentations on the condition, latest treatments and research, and answer members' questions.
The CMA has a long-established link with the Specialist Inherited Cardiovascular Disease Clinic run by Professor William J McKenna, a world expert in cardiomyopathy, at the Heart Hospital, London.
The association's work is recognised and supported by The BCPA, The British Heart Foundation, and The British Cardiac Society. Their freephone helpline is 0800 018 1024, 8.30am to 4.30pm on weekdays.
Cardio-pulmonary resuscitation CPR is a first aid technique using chest compression and artificial ventilation, used till an ambulance arrives. It gives some oxygen supply and is the best that can be done. Unfortunately CPR alone may not always start the heart beating again properly. CPR is unlikely to bring a casualty back to life, but can prevent damage to vital organs, thereby giving the casualty a fighting chance of eventual full recovery by the treatment the emergency services will give.
Some people have extended the meaning to include defibrillation with an automatic external defibrillator.
Cardiopulmonary arrest means the same as cardiac arrest, though the term implies breathing has stopped. In practice, if the heart is not beating the patient will also not be breathing.
Cardiovascular means relating to the heart and its associated blood vessels, and the circulation of blood.
Cardiovascular disease (CVD) includes coronary heart disease, stroke, and peripheral vascular conditions.
Cardioversion. See DC cardioversion.
Catalyst. A catalyst speeds up a chemical process, but usually does not itself get used up or changed chemically. Vitamin B6 is a catalyst for various body metabolism processes.
Catheter means a tube that is inserted into an artery and passes along the artery to the heart. See Angioplasty catheter, Valvuloplasty.
Cerebrovascular means of or relating to the blood vessels of the brain and the blood supply to the brain. Cerebrovascular disease means disease of these, eg stroke.
CHD stands for Coronary heart disease.
Cheese – See factsheet on Fat content of cheeses.
Chelating agent means a chemical used to treat a poison – eg metals such as arsenic, iron, lead, and mercury. It works by converting the poison to something less harmful, and/or causing the body to get rid of the original eg in urine. Penicillamine is a chelating agent.
Chemistry terms are explained under Proteins.
Chemotherapy is drug treatment of cancer.
Chest pain – causes other than heart attack It may be helpful to be able to distinguish the following different causes of chest pain, some of which are not heart related.
The italics below are symptoms or a possible question a first aider or carer might ask.
● Does your chest hurt when you physically exert yourself, and/or do you feel tightness in your chest, and/or does the pain sometimes also seem to be in your left arm, left shoulder or neck?
If so, this may be a heart-related issue. If such a pain starts suddenly and is severe this may be a heart attack, so send for an ambulance and do as above.
If the pattern has occurred several times, but perhaps mildly so there seemed no need for any treatment, contact your doctor – it may be angina from not enough blood reaching the heart muscles.
● Does your chest hurt when you move, cough and/or sneeze?
If so, the cause may come from the chest muscles, bones, or joints, or from an injury. Preferably avoid strenuous activity and take an anti-inflammatory pain reliever such as ibuprofen or paracetamol.
● Do you feel that your chest pain constricts your chest, and/or is the pain below the left breast?
If so, this may be due to anxiety or stress. So try to relax, take deep breaths, and try to do something about the reason for the stress.
● Does your chest hurt when you have food and/or hot drink, alcohol, and/or when lying down?
If so, this may be heartburn, which nothing to do with the heart.
● Do you have any red spots, rash, or blistering on your chest?
If so, this may be shingles, a disease affecting the tissues between the ribs, and caused by a reactivation of chickenpox. See your doctor, and if it is shingles, since anyone who has not had chickenpox could catch it from your shingles, please avoid contact with pregnant women.
Also, it may be meningitis – (test by pressing with a glass tumbler and if the red spots do not disappear when pressed on it is likely to be meningitis and hospital treatment is urgently needed), or Weil's disease if they have been near a river, lake, seaside, or sewage works.
● Is the pain worse when you take a deep breath?
If so, this may be an inflammation of the pleura, which are the membranes that cover the lungs and linings of the chest cavity. It may be caused by a chest infection. Various causes have similar symptoms, so see a doctor.
Cholesterol