Blood pressure (high) - Getting a blood pressure test

The only way to know if you have high blood pressure (hypertension) is to have your blood pressure checked.

This can be done by your GP or another healthcare professional, and you can also check it yourself with a home testing kit.

Healthy adults aged over 40 should have their blood pressure checked at least once every five years.

If you are at an increased risk of high blood pressure, you should have your blood pressure checked more often, ideally once a year.

Getting checked by your GP

Blood pressure checks are usually available on request at most GP surgeries and health clinics.

Blood pressure is often measured using a sphygmomanometer, a device which consists of a stethoscope, arm cuff, dial, pump and valve.

The cuff is placed around your arm and pumped up to restrict the blood flow. The pressure is then slowly released as your pulse is checked using the stethoscope.

Hearing how your pulse beats after the cuff is released allows a measurement to be taken on the mercury scale, giving an accurate reading of your blood pressure.

Many GP surgeries now measure your pulse using digital sphygmomanometers, which use electrical sensors. They must have been checked and validated according to national or international protocols for reliability. They are now the recommended devices for blood pressure measurement.

Before having your blood pressure taken, you should rest for at least five minutes and empty your bladder.

To get an accurate blood pressure reading, you should be sitting down and not talking when the reading is taken.

Blood pressure readings

Having one raised blood pressure reading does not necessarily mean you have high blood pressure. Blood pressure can fluctuate throughout the day. Feeling anxious or stressed when you visit your GP can raise your blood pressure.

Therefore, you will probably be given a blood pressure kit to take home so you can monitor your blood pressure level throughout the day. This will confirm whether you have consistently high blood pressure.

You may also have blood and urine tests to check for conditions that are known to cause an increase in blood pressure, such as kidney disease.

Home testing kits

Portable testing kits that measure your blood pressure at home or on the move can be a useful way of getting a more accurate reading.

This is because some people become anxious in medical clinics, which can cause the blood pressure to rise. This is a condition called white coat hypertension.

Home or portable blood pressure monitoring kits may show that your blood pressure is in fact normal when you are relaxed.

You can buy a variety of testing kits so you can monitor your blood pressure at home or while you're out and about.

It is important to buy a blood pressure monitor that is reliable and gives accurate readings. The British Hypertension Society (BHS) website has detailed information about clinically approved blood pressure monitors that are available to buy.

Understanding your blood pressure result

Blood pressure is measured in millimetres of mercury (mmHg) and it is recorded as two figures:

• systolic pressure – the pressure of the blood when your heart pushes blood out
• diastolic pressure – the pressure of the blood when your heart rests in between beats, which reflects how strongly your arteries are resisting blood flow

For example, if your GP says your blood pressure is "140 over 90" or 140/90mmHg, it means you have a systolic pressure of 140mmHg and a diastolic pressure of 90mmHg.

Ideally, your blood pressure reading should be below 120/80mmHg. However, anything under 130/80mmHg is generally considered normal.

You are said to have high blood pressure if readings on separate occasions consistently show your blood pressure to be 140/90mmHg or higher.

If you have kidney disease, diabetes or a condition that affects your heart and circulation, your target blood pressure should be below 130/80mmHg.

Find out how to treat high blood pressure.