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The heart pumps blood around the body through the blood vessels. Blood pressure is the amount of force exerted on the artery walls by the pumping blood. High blood pressure (hypertension) means that your blood is pumping with more force than normal through your arteries.

The added stress on the arteries can speed up the clogging of arteries with fatty plaques (atherosclerosis). Atherosclerosis contributes to many illnesses, such as heart attack and stroke. Other risk factors for atherosclerosis include cigarette smoking and high blood cholesterol.

Hypertension is a common disorder of the circulatory system, affecting around one in seven adult Americans and becoming more common with age. Older people may experience a change in their blood pressure pattern due to their arteries becoming more rigid (less elastic).

Hypertension usually produces no symptoms

This means most people don’t even realise they have it. Experts recommend that everyone should have their blood pressure checked regularly (preferably yearly).

When the heart contracts, the blood inside the left ventricle is forced out into the aorta and arteries.

The blood then enters small vessels with muscular walls, called arterioles. The tone in the muscular walls of the arterioles determines how relaxed or constricted they are. If narrowed, they resist flow.

Reduced flow of blood is detected in the brain, the kidneys and elsewhere. Nerve reflexes are stimulated and hormones are then produced. The heart is induced to beat more forcefully so that blood pressure is maintained at a higher level, to overcome the restricted flow through the arterioles.

The achievement of good flow (now at high pressure) eases possible problems for function of the brain and kidneys.

These adjustments occur normally

However, in some people the adjustments become fixed and high blood pressure persists.

These people have developed hypertension

Hypertension can be mild, moderate or severe. Your blood pressure is naturally higher when you are exerting yourself, such as during physical exercise. It is only a concern if your blood pressure is high when you are at rest, because this means your heart is overworked and your arteries have extra stress in their walls.

Blood pressure readings are a combination of two measurements. These are:

  • – is the highest pressure against the arteries as the heart pumps. The normal systolic pressure is usually between 110
  • 130mmHg

– is the pressure against the arteries as the heart relaxes and fills with blood. The normal diastolic pressure is usually between 70 and 80mmHg. Blood pressure is measured using an instrument called a sphygmomanometer.

An inflatable pressure bag is wrapped around the upper arm.

The bag is connected to the sphygmomanometer

The operator pumps up the bag with air until the circulation of the arm’s main artery is interrupted. The pressure in the bag is then slowly released until it equals the systolic pressure in the artery, indicated by blood once again moving through the vessel. This makes a ‘thumping’ sound.

The systolic pressure is indicated on the sphygmomanometer and recorded. The blood pressure in the arm’s main artery drops to equal the lowest pressure, which is the diastolic pressure. This is the pressure at which the thumping sound is no longer heard.

This figure is also recorded

The operator may take numerous readings to get the true picture. This is because many people tend to ‘tense up’ during the procedure and nervous tension may temporarily boost the blood pressure. The accuracy of electronic measuring and recording of both systolic and diastolic pressures is replacing manual and auditory blood pressure recording.

Hypertension usually does not produce any symptoms, because the organs of the body can resist high blood pressure for a long time. That’s why it’s important to have regular medical examinations to make sure your blood pressure isn’t creeping up as you grow older. High blood pressure over a period of time can contribute to many illnesses, including: stroke.

Some of the factors which can contribute to high blood pressure include:

  • changes in the arteries
  • but this remains scientifically uncertain

Certain drugs can cause hypertension or make controlling hypertension more difficult.

Check with your doctor or pharmacist for alternatives

  • some cough medicines eye drops appetite suppressants. With advancing years
  • the arteries tend to become more rigid (less elastic). This may change a person’s blood pressure pattern
  • with a higher systolic pressure
  • a lower diastolic pressure

The higher systolic pressure is important because it can further accelerate the rigidity of the arteries. This state is referred to as ‘isolated systolic hypertension’. Although these changes are due to ageing, this is not a normal state and may need medication to control the systolic pressures.

Two out of five people can successfully lower their blood pressure by making adjustments to their lifestyle.

For example, a low-fat diet and giving up cigarette smoking will reduce the damaging effects of hypertension on the arteries. Some healthy lifestyle choices include: Maintain your weight within the healthy range.

Eat a high-fibre, low-fat and low-salt diet.

Give up smoking

Limit alcohol consumption

Exercise regularly

See your doctor before you start any new exercise program. In most cases, it is necessary to take antihypertensive medication as well.

Usually hypertensive medication is introduced at low doses

The dose may be gradually increased if needed

A second or even a third drug may be added to achieve good blood pressure control.

Not many people experience unpleasant side effects

Any drug treatment for hypertension needs to be monitored carefully by your doctor. You should never alter the dose of your hypertension medication or stop taking it without consulting with your doctor. Medications don’t cure the condition and most of the people who need to take antihypertensive drugs will do so for the rest of their lives.

How blood pressure is controlled How blood pressure is measured Systolic Diastolic Sphygmomanometer Most people with hypertension feel okay heart attack heart failure kidney disease An unhealthy lifestyle can cause hypertension hereditary factors obesity lack of exercise a diet high in salt heavy drinking cigarette smoking high levels of saturated fat in the diet high blood cholesterol Some drugs may cause hypertension the combined contraceptive pill non-steroidal anti-inflammatories some nasal drops and sprays Blood pressure and ageing Making healthier choices Antihypertensive medications Where to get help Your GP (doctor) Your pharmacist.

Key Points

  • Other risk factors for atherosclerosis include cigarette smoking and high blood cholesterol
  • Hypertension usually produces no symptoms
  • operator pumps up the bag with air until the circulation of the arm’s main artery is interrupted
  • blood pressure in the arm’s main artery drops to equal the lowest pressure, which is the diastolic pressure
  • Certain drugs can cause hypertension or make controlling hypertension more difficult