Blood pressure (high)

The heart is a muscle that is designed to pump a constant supply of blood around the body.

The heart pumps blood that is low in oxygen towards the lungs, where it will receive more oxygen.

The heart also pumps oxygen-rich blood around the body so that oxygen can be used by the muscles and the cells in your body.

There are two measurements used to assess blood pressure:

• Systolic pressure is the blood pressure that is exerted when the heart beats and forces blood around the body.
• Diastolic pressure is the measure of blood pressure when the heart is resting between beats.

Blood pressure is defined as the amount of pressure exerted on the walls of the arteries as the blood moves through them. It is measured in millimetres of mercury (mmHg). Both the systolic and diastolic pressures are measured, and these figures are usually represented with the systolic pressure first, followed by the diastolic pressure.

So if your GP says that your blood pressure is '120 over 80', or 120/80mmHg, what they mean is that you have a systolic pressure of 120mmHg and a diastolic pressure of 80mmHg.

High blood pressure (hypertension)

High blood pressure (hypertension) is usually defined as having a sustained blood pressure of 140/90mmHg or above.

High blood pressure often causes no symptoms or immediate problems, but it is a major risk factor for developing a serious cardiovascular disease (conditions that can affect the circulation of blood around the body), such as a stroke or heart disease.

If you have high blood pressure, your heart has to work harder to pump blood around your body. Over time, this can weaken it. Also, the increased pressure can damage the walls of your arteries, which can result in a blockage or cause the artery to split (haemorrhage). Both of these situations can cause a stroke.

Who is affected by high blood pressure?

High blood pressure is common, with 40% of adults in England having the condition. The number of people who have high blood pressure increases with age. For reasons that are not entirely understood, people of Afro-Caribbean and South Asian (India, Pakistan and Bangladeshi) origins are more likely to develop high blood pressure than other ethnic groups.

In 95% of cases, there is no single identifiable reason for a raise in blood pressure. However, all available evidence shows that your lifestyle plays a significant role in regulating your blood pressure. Risk factors for high blood pressure include:

• Age.
• Excessive alcohol consumption.
• Poor diet.
• Lack of exercise.
• Obesity.

High blood pressure can be treated or prevented by making changes to your lifestyle, such as exercising more regularly, eating a healthier diet and cutting back on your consumption of alcohol. Medicines are also available that can help lower your blood pressure.