Checking your blood pressure at home

Some people are asked by a GP or nurse to keep an eye on their blood pressure at home. Others decide to buy a monitor for themselves.

High blood pressure does not usually cause symptoms. The only way to find out is to have it checked. These notes draw on the NHS, the British Heart Foundation (BHF) and the medicines and devices regulator.

Free checks

You do not need your own monitor to get a reading. Many pharmacies offer free blood pressure checks for people aged 40 or over. If your doctor wants you to check at home, they may be able to lend you a monitor and show you how to use it.

Choosing a monitor

The BHF gives a few pointers for choosing a home monitor.

Choose one that measures at the upper arm if you can. A wrist cuff is the fallback if an upper-arm cuff will not work for you.
Make sure the cuff fits. It should wrap snugly, with room to slide two fingers underneath. Most monitors come with a medium cuff, and other sizes are sold separately.
Look for a monitor validated by the British and Irish Hypertension Society. Validation means it has been tested to check its readings can be trusted.
Plan to have it serviced and calibrated at least every two years.

A pen and a paper diary record your readings just as well as a monitor with a memory.

Taking a reading

Sit upright with your back supported and your feet flat on the floor. Rest your arm on a table and keep your hand relaxed. Put the cuff on your upper arm. Try to relax, and do not talk while it inflates.

The NHS suggests taking a reading, noting it down, waiting a minute and taking another. This is usually done twice a day, in the morning and the evening. Your doctor or nurse will tell you for how many days.

What the numbers mean

A reading has two numbers, such as 130/80. The first is the pressure when your heart pumps. The second is the pressure when your heart relaxes between beats.

At home, a reading of 135/85 or higher is usually considered high. The figure for a check by a healthcare professional is 140/90 or higher. The NHS has a free tool that places your reading on a chart.

Monitors are medical devices

In the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) regulates medical devices. Devices must be registered with the MHRA before they are sold in Great Britain.