High blood pressure (hypertension) doesn't usually have any symptoms, so the only way to find out if you have it is to get your blood pressure checked.
Healthy adults aged over 40 should have their blood pressure checked at least once every five years.
If you're at an increased risk of high blood pressure, you should have your blood pressure checked more often – ideally once a year.
Having this done is easy and could save your life.
This page covers:
Where to get tested
What the test involves
Ambulatory (24-hour) monitoring
What your result means
Where to get a blood pressure test
You can ask for a blood pressure check – you don't have to wait to be offered one.
Blood pressure testing is available:
- at your GP surgery – by a GP, practice nurse, healthcare assistant or self-service machine
- at some pharmacies
- at an NHS Health Check appointment offered to adults aged 40-74 in England
- in some workplaces
- at a health event
You can also test your blood pressure at home using a home testing kit.
A stethoscope, arm cuff, pump and dial was normally used to measure your blood pressure, but automatic devices with sensors and digital displays are commonly used nowadays.
It's best to sit down with your back supported and legs uncrossed for at least five minutes before the test.
You'll usually need to roll up your sleeves or remove any long-sleeved clothing so the cuff can be placed around your upper arm. Try to relax and avoid talking while the test is carried out.
During the test:
- you hold out one of your arms so it's at the same level as your heart, and the cuff is placed around it – your arm should be supported in this position with a cushion or the arm of a chair, for example
- the cuff is pumped up to restrict the blood flow in your arm – this squeezing may feel a bit uncomfortable, but only lasts a few seconds
- the pressure in the cuff is slowly released and detectors sense vibrations in your arteries – a doctor will use a stethoscope to detect these if your blood pressure is measured manually
- the pressure in the cuff is recorded at two points as the blood flow starts to return to your arm – these measurements are used to give your blood pressure reading
You can usually find out your result straight away, either from the healthcare professional carrying out the test or on the digital display.
If your blood pressure is high, you may be advised to record your blood pressure at home to confirm whether you have high blood pressure.
Ambulatory (24-hour) monitoring
Having a raised blood pressure reading in one test doesn't necessarily mean you have high blood pressure.
Blood pressure can fluctuate throughout the day. Feeling anxious or stressed when you visit your GP can also raise your blood pressure.
If you have a high reading, you may be asked to take some readings with a home blood pressure monitor or wear a 24-hour monitor that checks your blood pressure throughout the day. This will confirm whether you have consistently high blood pressure.
This is known as 24-hour or ambulatory blood pressure monitoring (ABPM).
Blood pressure tests can also be carried out at home using your own digital blood pressure monitor.
Like 24-hour or ambulatory monitoring, this can give a better reflection of your blood pressure. It can also allow you to monitor your condition more easily in the long term.
You can buy a variety of low-cost monitors so you can test your blood pressure at home or while you're out and about.
It's important to make sure you use equipment that has been properly tested. The British Hypertension Society (BHS) has information about validated blood pressure monitors that are available to buy.
Understanding your blood pressure reading
Blood pressure is measured in millimetres of mercury (mmHg) and is given as two figures:
- systolic pressure – the pressure when your heart pushes blood out
- diastolic pressure – the pressure when your heart rests between beats
For example, if 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.
As a general guide:
- high blood pressure is considered to be 140/90mmHg or higher (or an average of 135/85mmHg at home)
- ideal blood pressure is considered to be between 90/60mmHg and 120/80mmHg
- low blood pressure is considered to be 90/60mmHg or lower
A blood pressure reading between 120/80mmHg and 140/90mmHg could mean you're at risk of developing high blood pressure if you don't take steps to keep your blood pressure under control.
Find out more about what your blood pressure result means.