Blood pressure test

Why a blood pressure test is done

A blood pressure test can check if your blood pressure is too high or too low.

High blood pressure (hypertension) can cause serious problems like strokes or heart disease, but it does not usually have any symptoms. The only way to find out if you have high blood pressure is to get it checked.

Low blood pressure (hypotension) can cause symptoms such as dizziness or fainting.

You may be given a blood pressure test:

• if a doctor thinks you may have high or low blood pressure
• as part of a general health check
• to check if high blood pressure is linked to other conditions you may have
• if you're taking medicine for a long-term condition
• if you're in hospital to check your health
• if you're pregnant as part of your antenatal care

It's particularly important to get your blood pressure checked if you're at higher risk of high blood pressure, for example if:

• you're aged 40 or over
• you're from a Black or South Asian background
• you have close relatives who have high blood pressure
• you smoke, drink too much alcohol or caffeine, or eat too much salt
• you're living with obesity

Where to get a blood pressure test

You can have your blood pressure checked at:

• most pharmacies
• your GP surgery
• some workplaces

Some pharmacies may charge for a blood pressure check.

What happens when you have a blood pressure test

A blood pressure test usually takes a couple of minutes. You'll be asked to:

1. Sit down and roll up your sleeve, or remove any long-sleeved clothing.
2. Outstretch your arm, rest it on a table and relax.
3. Have an inflatable armband (cuff) wrapped around your upper arm.
4. Stay in that position while the armband fills with air – this may feel uncomfortable for a few seconds until the air releases.

Devices can be different but the armband is usually connected to a small machine that shows your blood pressure measurements.

The test may be done a couple of times to make sure the measurement is accurate.

Checking your blood pressure at home

If a doctor or nurse needs you to check your blood pressure at home, they may give you a blood pressure machine to use. They will show you how to use it.

You can also buy your own blood pressure machine to use at home. Machines may be slightly different, so follow the instructions on how to use it to record your blood pressure.

Take your blood pressure, make a note of the numbers, then wait 1 minute before doing it again. You usually do this 2 times, once in the morning and once in the evening. Your doctor or nurse will tell you how many days you need to do this.

If your blood pressure needs to be monitored for 24 hours, you may be given a monitor to wear at home. You'll need to go to a GP surgery, health centre or hospital to have this put on and to return it the next day. Wearing it at home will not affect your daily activities.

What your blood pressure result means

Blood pressure readings are given as 2 numbers, with the 1st number higher than the 2nd (for example,130/80).

The first number measures the systolic pressure. This is the highest level your blood pressure reaches when your heart pumps blood around the body.

The second number measures the diastolic pressure. This is the lowest level your blood pressure reaches when your heart relaxes between each heartbeat.

Your blood pressure is usually considered high if it's either:

• 140/90 or higher when checked by a healthcare professional
• 135/85 or higher when checked at home

You can lower high blood pressure by making healthy lifestyle changes, such as eating healthily, exercising regularly and cutting down on alcohol.

Many people also need tablets to control their blood pressure. A doctor will recommend the most suitable medicine for you if needed.