What is hypertension?
Hypertension is the medical term used for high blood pressure. It is not a good term in that it suggests that high blood pressure is caused by stress, or 'tension', which is not the case. Stress and anxiety may cause a rise in blood pressure, but this is usually transient, returning to normal once the stress has passed.

How will I know if I have high blood pressure?
There are few, if any symptoms associated with high blood pressure, and the only way you can find out if you have high blood pressure is by having it measured.

Why should I bother to have my blood pressure measured?
High blood pressure causes insidious silent damage to the blood vessels and the heart. If untreated this damage progresses over time and may result in stroke or heart attack. These serious events occur at a younger age in people with high blood pressure than in people with normal blood pressure.

Can stroke and heart attack be prevented?
The answer is - YES! The reason doctors want to detect people with high blood pressure is that it is now well established that if high blood pressure is brought down to normal the damage to the cardiovascular system is halted and may even be reversed, and therefore stroke and heart attack are prevented, or at least postponed.

How can blood pressure be measured?
Blood pressure is measured with an instrument known as a sphygmomanometer. The traditional sphygmomanometer consists of a cuff, which is wrapped around your arm and then inflated to a certain pressure with a hand pump. The pressure is read in millimetres of mercury read on a glass column. As the pressure is released, sounds may be heard with a stethoscope placed over an artery on the front of the arm - the brachial artery; this is the pressure when the heart contract - the systolic blood pressure, and when the sounds disappear, the lowest pressure when the heart is relaxing is reached - the diastolic blood pressure. Due to concerns about the toxicity of mercury, all new sphygmanometers are mercury free. these new machines use microphones to hear the sounds disappear or an oscilloscope which senses motion from the occulded artery in order to record the blood pressure.

What figure constitutes high blood pressure?
There is a move away from relying excessively on so-called casual blood pressure measurements - those obtained, for example, on your first visit to a doctor. It is now known that blood pressure taken under such circumstances may be unduly high due to anxiety, but that it may return to normal as soon you leave the medical environment. This is called 'white coat hypertension'. For this reason your doctor will want to measure your blood pressure on number of occasions and he will probably want to have a recording of your blood pressure made over 24-hours - ambulatory blood pressure measurement, before making a decision either to diagnose you as having high blood pressure, or to prescribe treatment. A general figure for normal blood pressure is a pressure below 130/85 mmHg.

What causes high blood pressure?
For most people with high blood pressure - say 90% - there is no demonstrable cause for the elevation of pressure, and in most cases it is genetically determined. Such people will often have a family history of high blood pressure. In a small number of people a cause can be demonstrated with special investigations. This cause may be in the kidney or in the endocrine system - the glands that secrete the hormones controlling blood pressure, but in most people there is no cause and is referred to as "essential" hypertension.

What will my doctor do?
When you go to see your doctor and ask for your blood pressure to be checked, a cuff will be used to measure your blood pressure. If this is normal you will be reassured and asked to return in a year or so for a further check - all our blood pressures rise with age! If your blood pressure is high, you will probably be asked to return for a repeat blood pressure measurement, and if this is high you may be sent for some investigations, including ambulatory blood pressure measurement over 24-hours which will tell your doctor if the blood pressure rise is sustained, or merely a response to the circumstances of measurement - white coat hypertension. If this is the case, you may be reassured but will be asked to return, perhaps in a year, for a repeat assessment.

If your doctor decides that you do have high blood pressure, you may be sent for some further investigations and drug treatment may be started.

What is white coat hypertension?
White coat hypertension occurs in as many as 20 per cent of people with high blood pressure. What happens is that these people have a high blood pressure in the presence of a doctor or nurse, or in a hospital, but when they get away from the medical environment their blood pressures return to normal.  This condition only became apparent with the development of devices capable of measuring blood pressure over 24-hours. So your doctor may ask you to have an ambulatory blood pressure monitor or ABPM, as it is called, to see if your blood pressure is really what it appears to be from the clinic measurement.

Is white coat hypertension harmless?
People with white coat hypertension are at much lower risk than people with sustained elevation of blood pressure, but they may develop high blood pressure later in life. So whereas people with white coat hypertension may not require drug treatment at the time of diagnosis, they may develop sustained high blood pressure later in life and annual checks on blood pressure are therefore important.

Will I need tablets?
This depends on the level of your blood pressure and perhaps also on the effect that the rise in blood pressure has had on your heart and blood vessels. Other factors will also be taken into account, such as your family history, and the presence of other risks, such as smoking, overweight, cholesterol levels or diabetes.

But why tablets?
If your doctor told you that a tablet was available to prevent ageing, you would rush out to get it - along with everyone else! This is exactly what blood pressure lowering drugs do - they prevent premature ageing of the cardiovascular system, on which the brain, heart and every other organ depend on for survival. If you look on blood pressure lowering tablets in this way, you will see them as preventive rather than necessary as 'treatment'.

How serious a risk is salt?
The answer is that the evidence is accumulating to indicate that salt is an important factor in causing high blood pressure. Our intake of salt and cholesterol is too high. So do not add salt to your food and check the salt content of the foods you buy. So-called ‘junk’ foods can be very high in salt.

How serious a risk is weight?
People who are overweight have higher blood pressures than thin people and reducing weight helps to bring your blood pressure down. In people who are very overweight it becomes difficult to measure blood pressure accurately because of the increased arm circumference.This may result in underestimation of your blood pressure and so the doctor should use a larger cuff size to wrap around your upper arm.

Should I take exercise?
Most people with high blood pressure can lead perfectly normal lives, except for having to modify risk factors and perhaps take a tablet each day. So if you like exercise, your doctor will encourage you to continue with this. If you don’t take much exercise you will be encouraged to do so. The evidence that exercise prevents cardiovascular disease is somewhat less convincing than cigarette cessation, but it certainly helps to improve a sense of general well-being and is encouraged as part of a programme of risk factor modification.

What investigations will be done?
Your doctor will first take your history and examine you. You will be sent for an examination of your urine and blood to exclude kidney disease and diabetes mellitus, and you will have a fasting blood test to determine the level of your cholesterol and other fats in the blood. Your doctor may arrange for you to wear a small device that will record your blood pressure over 24-hours, or you may be asked to measure your blood pressure at home. You will also have an electrocardiograph (ECG), and possibly echocardiography; these test give information on the state of your coronary arteries and the size of the pumping chamber of your heart - the left ventricle - which may enlarge to cope with the high blood pressure. If your doctor suspects an underlying cause for your high blood pressure he may refer you for some specialised tests, but this is only necessary in a small number of people with high blood pressure or blood pressure that does not respond to therapy.

What drugs will I be given?
You may not need any drugs. Sometimes risk factor modification alone may be sufficient, especially when blood pressure elevation is mild. However, if you need drugs, your doctor has a broad selection from which  chose. The choice will be influenced by a number of factors, such as the level of your blood pressure and whether you haev other problems such as a history of asthma, heart disease, diabetes or gout, in which certain drugs may be more appropriate than others.

How often will I need to take tablets?
Most drugs for lowering high blood pressure are effective over the 24-hour period, so you will probably only need to take a tablet in the morning.

Will I need more than one tablet?
In the majority of people with high blood pressure, one tablet taken in the morning will suffice, but when high blood pressure is resistant to treatment, more than one tablet may be required. There is evidence that low doses of two blood pressure lowering drugs are more effective than either given alone, and combination preparations are commonly used to reduce blood pressure. Again these are usually given as one tablet daily.

Can I expect side-effects from tablets?
All drugs can cause side-effects, but blood pressure lowering drugs have been improved greatly over the last decade, so that they exert their blood pressure lowering effect without producing too many unwanted effects. None-the-less, we each react differently to medication, and in a small number of people with high blood pressure, the treatment will cause side effects. What is important is that if you develop what may be side-effects you should tell your doctor rather than suffering in silence or stopping the drug. An alternative drug can then be selected which will not cause unwanted effects.

Will my sex life be affected?
Possibly but for two reasons. First, high blood pressure itself may reduce sexual drive, and secondly, some drugs that lower blood pressure also reduce sex drive. If this happens be sure to discuss it with your doctor as again there may be alternative therapies that reduce yoru blood pressure but do not affect your sex drive. 

How will I know if the tablets are being effective?
There are four ways in which your doctor can assess the effect of the blood pressure lowering drug you are taking. First, your blood pressure can be measured at return visits to your doctor. Alternatively, you may be advised to measure your own blood pressure at home and this gives a broader estimate of blood pressure reduction over time. Ambulatory blood pressure measurement (ABPM) over 24-hours gives the most comprehensive assessment of the efficacy of the drug you are taking. ABPM also shows if the drug is being effective over the 24-hour period, and it can detect any excessive lowering of blood pressure. Finally, your doctor can assess the longer-term effect of treatment by showing that abnormalities of the cardiovascular system, such as enlargement of the heart on echocardiography, which may have been present before treatment, has improved after a period of time on treatment.