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Persistent high blood pressure (hypertension)

Causes Prevention Risk Factors Drugs Lifestyle changes

High blood pressure is important as if untreated puts you at greater risk of having a heart attack (myocardial infarction) or stroke.
To measure blood pressure, two readings are taken:

The systolic pressure. This is the first and higher measurement. It is a measure of the blood pressure as the heart contracts and pumps blood out.

The diastolic pressure. This is the second and lower number. It is a measure of the blood pressure when the heart is relaxed and filling up with blood.Blood pressure is measured in terms of millimetres of mercury (mmHg). Hypertension (high blood pressure) is defined as a systolic pressure of 140 mmHg or more, or a diastolic pressure of 90 mmHg or more.

Blood pressure varies constantly during the day. The level of physical exertion, anxiety, stress, emotional changes and other factors may also cause changes in blood pressure. So blood pressure should be checked under resting conditions and single measurements are not particularly meaningful. A diagnosis of hypertension is not normally made unless a high blood pressure is measured on three separate occasions (usually over 3 months).
Lifestyle changes, such as a healthy diet and increased exercise are important for everyone with raised blood pressure. Medicines to treat hypertension are particularly recommended for a sustained systolic pressure of 160 mmHg or more and/or diastolic pressure 100 mmHg or more.

High blood pressure is common. Moderately high diastolic pressures (90-109 mmHg) are found in about 1 in 4 middle-aged people. They are less common in younger people and more common in those who are older. Very high diastolic pressures (110-129 mmHg) are found in about 1 in 25 people. It is believed that there are large numbers of people who have high blood pressure but are not aware of it.

Symptoms Most people with hypertension will not get any symptoms. The only way to find out if you have high blood pressure is to have it measured.
In rare cases, the blood pressure can rise dramatically and without warning. The systolic blood pressure can reach 220mmHg and the diastolic pressure 120mmHg.
Urgent treatment is required. This happens to less than 1 in 100 people who have hypertension. The symptoms of this type of severe high blood pressure include:
a bad headache, feeling confused, feeling sick, having trouble seeing, feeling very sleepy.


High blood pressure is very common, affecting as many as 1 in 4 people.
In approximately 90% of cases, the cause is unknown. This type of high blood pressure is known as ‘essential hypertension’.
Certain lifestyle and genetic factors may contribute to the risks of developing essential hypertension.
Risk factors include:
getting older, being male - hypertension is slightly more common in men, having a family member with high blood pressure, being overweight, drinking excessive amounts of alcohol, stress, smoking, lack of exercise. ethnic group- as many as half of all people of black African or Caribbean origin over 40 years of age are likely to have high blood pressure

Likewise British people of South Asian (Indian, Pakistani or Bangladeshi) origin are also more likely to have high blood pressure and are more prone to stroke and heart attacks.In a few people, the cause of hypertension can be identified. The cause may be Cushing's syndrome, kidney disease, taking certain medicines e.g. oral contraceptives or, rarely, a tumour of the adrenaline-producing cells in the adrenal gland (small gland above the kidney).


The aim of treatment is to keep the diastolic blood pressure less than 85mmHg and the systolic blood pressure less than 140 mmHg.
These targets are set slightly lower, diastolic less than 80 mmHg and systolic less than 135 mmHG, for people at greater risk of heart attack (myocardial infarction) and stroke e.g. if you have angina, a previous heart attack, chronic renal failure or diabetes.
In some people, it may not be possible to reduce the blood pressure below these targets, despite treatment.
Lifestyle changes
In many cases, mild high blood pressure can be treated with lifestyle changes. See the 'Prevention' section.
Losing weight, regular exercise, a low-fat and low salt diet, quitting smoking and reducing the amount of alcohol consumed will often be enough to get blood pressure down to normal levels.
Antihypertensive medicines
If lifestyle changes are not successful, then antihypertensive medicines will be necessary. Antihypertensive medicines are particularly recommended if the systolic pressure is 160 mmHg or more and/or the diastolic pressure is 100 mmHg or more.
There are different antihypertensive medicines and your doctor will assess which type is best for you start on.
A single antihypertensive medicine may not be adequate and others will be added one by one until good blood pressure control is achieved. Unless it is necessary to lower the blood pressure urgently, an interval of at least 4 weeks is usual before adding in more treatment.
Antihypertensive medicines can have side effects. However, it is important to continue with treatment. Discuss any side effects with your doctor, as there are options of different antihypertensive medicines which suit you better.
Treatment should be regularly reviewed. If you make lifestyle changes and your blood pressure has returned to a normal level, your GP may advise you to cut down or come off antihypertensive medicines for a trial period.

Antihypertensive medicines include:
Thiazide diuretics ('water tablets') e.g. bendroflumethiazide, chlortalidone, indapamide, metolazone are usually the first choice antihypertensive medicine for people over 55 years. They work by flushing excess water and salt from your body via the urine. With long-term use, they also open up the blood vessels.
Beta-blockers e.g. atenolol, bisoprolol, metoprolol, propranolol, work by making the heart beat more slowly and with less force, so lowering the pressure in your arteries. Some beta-blockers also block renin, a chemical in the kidney that controls the loss of sodium and water.
Angiotensin-converting-enzyme inhibitors (ACE inhibitors) e.g. captopril, enalapril, lisinopril, perindopril, ramipril.
Blood pressure is controlled in part by angiotensin, a natural chemical produced by the kidney. Angiotensin causes the blood vessels to narrow and so raise the blood pressure. ACE inhibitors lower your blood pressure by stopping the formation of angiotensin.
About a third of all people taking ACE Inhibitors get a persistent dry cough. If this occurs, an alternative type of antihypertensive medicine should be tried.
Angiotensin II receptor antagonists e.g. candesartan, losartan, valsartan work similarly to ACE Inhibitors. Instead of blocking the formation of angiotensin II, they prevent the chemical from working at its site of action.
They are an alternative for people who experience a cough with ACE inhibitors.
Calcium channel blockers e.g. amlodipine, diltiazem, nifedipine, nicardipine, verapamil keep your blood vessels relaxed and open, making it easier for blood to flow through them. This lowers the blood pressure. Some calcium channel blockers also make the heart beat more slowly.
Alpha blockers e.g. doxazosin, prazosin, terazosin keep the blood vessels relaxed and open, making it easier for blood to flow through them. This lowers your blood pressure.
Some people feel faint after taking the first few doses of an alpha-blocker. For this reason, it is best to take the first few doses at night just before going to bed. Also, the doctor will usually start you on a low dose and gradually increase the dose as you get used to it.

Medicines to reduce the risk of heart attack and stroke
Statins e.g. atorvastatin, fluvastatin, pravastatin, rosuvastatin, simvastatin lower the blood cholesterol level by preventing cholesterol from being made in the liver. For people with high blood pressure, the aim is to reduce the total blood cholesterol level to below 4 mmol/l or by 25% of the original blood level whichever gives the greatest reduction.
Generally, the higher the blood cholesterol level, the greater the risk of atherosclerosis (fatty deposits in the arteries). Atherosclerosis causes narrowing of the arteries (blood vessels) which when combined with high blood pressure can put you at a greater risk of heart attack and stroke.
Low dose aspirin
Taking low dose aspirin, usually 75mg, when you have high blood pressure helps to reduce the risk of having a heart attack or stroke.
Low dose aspirin reduces the 'stickiness' of platelets (tiny particles in the blood that help the blood to clot). When a large number of platelets stick to an atheroma (fatty deposit) inside an artery, they can form a thrombosis (clot). If a clot forms in an artery to the heart muscle, it can cause a heart attack or in an artery to the brain, a stroke


You can help treat and reduce your risk of developing high blood pressure by making lifestyle changes:
eat a healthy, well-balanced diet, with less salt, lose weight if necessary, exercise regularly, stop smoking, reduce your alcohol and caffeine consumption to recommended levels.Regular checks of your blood pressure are important, especially if you have a family history of hypertension. Treatment can then be started before complications have a chance to develop.




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