Think of high blood pressure – or hypertension as doctors call it – and you probably think headaches, dizzy spells and a florid complexion.

However, most people with high blood pressure have no pain, no symptoms and many will not even know that their blood pressure is high.

Four in every 10 men and women have hypertension, but about 80% of them are not being treated for it. Yet hypertension can be fatal. It dramatically increases your risk of developing heart and kidney disease and increases your risk of stroke and heart failure sixfold.

What causes hypertension?

In most cases the cause isn’t known. However, there are a number of known risk factors which make you more susceptible, these include:

*family history of hypertension
*stroke or heart attack
*taking little or no exercise
*binge or heavy drinking
*poor diet.

A 10-year study of more than 200,000 people found that the more overweight a person was, the more likely he or she was to have high blood pressure.

Black people are also more vulnerable to hypertension – research suggests that they are more sensitive to salt in the diet and have a higher risk of stroke.

If you are south Asian you have a higher risk of diabetes and heart attack, so it is vital that your blood pressure is well controlled.

Does stress matter?

Although stress makes blood pressure rise temporarily, there’s doubt about whether it can contribute to a long-term increase.

New US research suggests that personality type may be significant. A study published in the Journal of the American Medical Association found that impatience and hostility (hallmarks of a “type A” personality) in young adults increase their long-term risk of developing high blood pressure.

How high is too high?

Blood pressure, the force of blood against the artery walls, is measured in millimetres of mercury (mm Hg) and recorded as two numbers – the systolic pressure (as the heart beats) over the diastolic pressure (as the heart relaxes between beats).

The first figure is the most important measure in older people. As we age we are more likely to have a raised systolic pressure while the diastolic pressure remains normal – this is known as isolated systolic hypertension and still needs treatment.

Blood pressure is considered high if it is over 140/90 but you should be concerned if it’s in the upper range of normal – 130/85 – and take measures to bring it down, as the risk rises when systolic pressure goes over 110.

Take control

Have your blood pressure checked regularly. Learn what the figures mean and if it’s on the high side talk to your doctor about ways to lower it.

The Blood Pressure Association recommends that anyone in the upper normal range is checked annually.

If you have hypertension your doctor will check it more often. If your pressure is at the lower end of the normal range – 120/80 or below – have it checked every three or four years.

Lifestyle changes

A high salt diet pushes blood pressure up and most people in the UK eat twice the recommended daily 6g of salt, three quarters of this coming from processed and takeaway foods. It has been estimated that cutting salt intake by 3g a day would reduce strokes by 13% and heart disease by 10%.

Aim to eat seven or eight portions of fruit and vegetables daily. As well as being rich in anti-oxidants, which help protect against arterial damage, they are good sources of potassium which has been shown to help lower blood pressure.

Drink sensibly, limiting your intake to 21 units of alcohol a week for men, 14 for women.

Exercise can prevent or delay the development of hypertension and reduce high blood pressure. It will also keep your weight down, strengthen your heart, reduce levels of harmful LDL cholesterol and help boost beneficial HDL cholesterol.

Better treatment

Almost all hypertension can be controlled with the right treatment. Most people start with a diuretic, which gets rid of salt and water from the body, but a combination of drugs often works best.

Options include beta-blockers which slow the heartbeat, calcium channel blockers which open up the blood vessels making it easier for the heart to work, alpha blockers which block receptors in the blood vessels lowering blood pressure and ACE inhibitors and Angiotensin Receptor Blockers which both work by preventing the release of a hormone which in turns helps open up blood vessels.