High blood pressure (hypertension) does not usually have any symptoms. The only way to find out if you have it is to get your blood pressure checked.
If you are 40 years or older, have your blood pressure checked at least once a year.
Having this done is easy and could save your life.
Have your blood pressure checked at least once every 5 years if you’re 18 to 39 years and you're healthy with no family history of high blood pressure.
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
- at some pharmacies
- in some workplaces
- at health events
You can also test your blood pressure at home using a home testing kit.
Having a blood pressure test
A stethoscope, arm cuff, pump and dial are used to measure your blood pressure. Automatic devices with sensors and digital displays are also now used.
Sit down with your back supported and legs uncrossed for at least 5 minutes before the test.
You'll usually need to roll up your sleeves or remove any long-sleeved clothing. This is so the cuff can be placed around your upper arm. Try to relax and avoid talking during the test.
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. It will only last a few seconds
- the pressure in the cuff is slowly released - detectors sense vibrations in your arteries
- a stethoscope is used to detect these if your blood pressure is measured manually
- the pressure in the cuff is recorded at 2 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. You'll get it from the healthcare professional or on the digital display.
Ambulatory (24-hour) blood pressure monitoring
Having a raised blood pressure reading in 1 test does not 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. You may have to wear a 24-hour ambulatory blood pressure monitor that checks your blood pressure throughout the day.
This will confirm if you have consistently high blood pressure.
Home blood pressure testing
You can also do blood pressure tests at home using your own blood pressure monitor.
This can give a more accurate measure of your blood pressure than one-off blood pressure readings in your GP's surgery.
It can also make it easier to monitor your condition over time.
You can buy a low-cost monitor so you can test your blood pressure at home or while you're out and about.
Measure your blood pressure twice a day. It's best to do it in the morning and the evening, while you're sitting down.
Each time take 2 readings, 1 minute apart. Continue to measure your blood pressure twice a day for 7 days.
Your GP or nurse will use this information to work out your average blood pressure.
It's important to make sure you use equipment that's been properly tested.
An independent non-profit organisation STRIDE-BP provides a list of recommended and tested devices approved for home use.
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. This means you have a systolic pressure of 140mmHg and a diastolic pressure of 90mmHg.
As a general guide:
- high blood pressure is 140/90mmHg or higher (or an average of 135/85mmHg at home). If you're over the age of 80, high blood pressure is 150/90mmHg or higher (or an average of 145/85mmHg at home).
- ideal blood pressure is usually considered to be between 90/60mmHg and 120/80mmHg. The target for over-80s is below 150/90mmHg (or 145/85mmHg at home)
Blood pressure readings between 120/80mmHg and 140/90mmHg could mean you're at risk of developing high blood pressure if you do not take steps to keep your blood pressure under control.