Advice / Information About Blood Pressure

What is blood pressure?

Blood pressure is the pressure of blood in your arteries. The heart pumps blood around your body through a network of arteries, by contracting and then relaxing. When the heart contracts the blood is forced through the arteries and your blood pressure goes up. This is when your blood pressure is highest and is called the systolic pressure. When your heart relaxes (between heart beats), your blood pressure goes down. This is when the pressure is lowest and is known as the diastolic pressure. These two pressures are written as numbers, one over the other, like a fraction - eg.140/85 mmHg. The top number is the systolic pressure and the bottom number is the diastolic pressure.


Why is blood pressure important?

Blood pressure is a valuable indicator of how at risk you are of certain life threatening conditions. If your blood pressure is high there is an increased risk of coronary heart disease and stroke. Coronary heart disease is the number one cause of death in the UK, and strokes are a major cause of long term disability and may sometimes lead to death.

The following table shows how the likelihood of heart disease and stroke increases with a higher blood pressure. The figures shown are the two figures displayed when you take your blood pressure using a blood pressure monitor.
 

BP Advice Body

What causes high blood pressure?

High blood pressure develops if the walls of the larger arteries lose their natural elasticity and become rigid, and the smaller blood vessels become narrow. Factors can be:

- Not doing enough physical activity
- Being overweight
- Too much salt in your diet
- Drinking too much alcohol
- Not eating at least five portions of fruit and vegetables each day
- Family history
- Stress
- Occasionally some medications used to treat ulcers, arthritis or depression may cause a rise in
blood pressure. In over nine out of every ten people there is no definite cause of high blood
pressure.

What are the symptoms of high blood pressure?

High blood pressure rarely makes people feel ill. It can cause headaches in a very small number of people, but only if their blood pressure is very high. Occasionally nose bleeds and eye problems may be due to high blood pressure, although most people experience no symptoms at all. The only way to know your blood pressure is to have it measured, or to measure it yourself.

How is blood pressure measured?

Blood pressure is measured using a sphygmomanometer (pronounced sfig-mo-man-ometer). This is usually a digital blood-pressure monitor, which is made up of a box with a tube leading to a cuff. The cuff is wrapped around your upper arm, and at the press of a button will inflate to a certain level and then deflate. A sensor in the cuff detects your pulse rate and changes the information into blood pressure readings that appear on a display screen.

What should my blood pressure be?

Your target is to have a blood pressure below 140/85 mmHg. Readings above this level are generally considered to be high. High blood pressure is also known as hypertension. In contrast, low blood pressure, or hypotension, is when the systolic blood pressure is below 90-100mmHg and the diastolic below 60mmHg of mercury.

How is high blood pressure treated?

It is helpful to look at areas of your lifestyle that can cause high blood pressure such as reducing your weight, eating at least five portions of fruit and vegetables a day, cutting down on salt and alcohol, stopping smoking, and being more physically active. For tips on how to bring about these changes, visit www.bpassoc.org.uk.
If your blood pressure remains high in spite of these measures, you may need to take medication recommended by your doctor.

White coat hypertension

Some people feel anxious and apprehensive when visiting the doctor, and tend to have a higher blood pressure when the doctor measures it. This is called "White coat hypertension" and may affect 10-20% of patients. It can be diagnosed by patients measuring their own blood pressure with an accurate monitor at home, or with a 24-hour ambulatory blood pressure recording (which your doctor will provide).

When is it best to measure blood pressure?

Blood pressure varies considerably from hour to hour throughout the day, being highest in the morning and lowest at night. Blood pressure tends to rise with age and also with anxiety and exercise, so it is best to record your measurements when you are rested and relaxed.

What other organisations can be contacted?

For more information on blood pressure and blood pressure monitors, you can contact:

The Blood Pressure Association
60, Cranmer Terrace
Tooting
London
SW17 OQS
Web: www.bpassoc.org.uk


You may also like to request a booklet called ‘Blood Pressure' from the British Heart Foundation at www.bhf.org.uk.

What types of home blood pressure monitor are there?

If you have high blood pressure (hypertension), your doctor may advise you to measure your own blood pressure using a home monitor. The easiest type to use at home is the increasingly popular digital electronic sphygmomanometer. This has an arm cuff, and an electronic monitor that shows your reading. You can also get wrist-worn blood pressure monitors, though these are considered to be less accurate. However, their more compact size means that they are easily portable for readings anytime, anywhere.

How do I use it?

Blood pressure monitors are generally quite easy to use. But it is a good idea to get a health professional to show you how to use yours correctly. This way you will avoid taking inaccurate readings, which can cause unnecessary anxiety. You must remember that any single reading does not provide an accurate picture of your blood pressure, as your levels will vary naturally throughout the day. By taking regular readings at the same time of day you will, over time, have a good measure of your blood pressure level.

What are the benefits of measuring my own blood pressure?

Measuring your own blood pressure means that you can be more actively involved in your own care. It can help you to manage your drug treatment and your lifestyle. If you get ‘white coat hypertension’, which is when your blood pressure is higher than usual when measured in a clinical setting by a health professional, you can benefit from taking your blood pressure yourself in the relaxed and familiar surroundings of your home.

How do I choose a blood pressure monitor?

There are lots of monitors on the market. It is important to choose one you are comfortable with. Electronic monitors start at around £45. Ideally you should make sure that the model you choose has been tested in the UK. The following monitors have been approved by the British Hypertension Society (BHS), a independent body that is widely considered a world authority concerning blood pressure. The list is compiled from research papers and not from direct testing but you may find it helpful as a guide.
 

BHS Blood pressure monitor list

Blood pressure risk factors

Reading	Risk
115/75	Normal
135/85	Twice as likely
155/95	Four times as likely
175/105	Eight times as likely