HealthInfo Canterbury
Measuring your blood pressure at home
Home blood pressure testing is when you measure your blood pressure in your home under a health professional's guidance.
Home blood pressure measurements can help:
- when your GP suspects you may have high blood pressure due to anxiety from being measured at your GP's surgery
- when there's a big variation in your blood pressure measurements between visits
- to check whether your medication is working or if it's causing low blood pressure (hypotension)
- when you aren't responding to blood pressure-lowering treatments.
How to choose a blood pressure monitor
If you're measuring your blood pressure at home, you need to use a validated blood pressure monitor. Validated means the monitor has been confirmed to give accurate and reliable results.
Devices for home monitoring usually inflate automatically when you push a button. There are some manual models where you need to inflate the cuff yourself by pumping a bulb.
Devices that measure blood pressure at your upper arm are considered to be more reliable than those that measure blood pressure at your wrist or finger. Rarely, some people need to use a validated wrist device if they have a large arm.
It's important to choose the right cuff size. Cuffs are available in small, medium and large sizes. Using the wrong cuff size can give you incorrect blood pressure readings. A cuff that's too small will overestimate blood pressure and a cuff that's too large will underestimate blood pressure.
If you aren't sure about the accuracy of your blood pressure monitor, take it to your GP's office or a pharmacy. There, the staff can compare your monitor's reading to their own device.
Tips on how to measure your blood pressure
- Measure your blood pressure the same way each time.
- It's best to measure your blood pressure in a quiet room after you've been sitting for five minutes. Your arm should be relaxed.
- Sit with your feet flat on the floor, legs uncrossed and your upper arm bare. Make sure your back and arm are supported in a relaxed position, with the cuff at heart level.
- Take two consecutive measurements one to two minutes apart. Taking one set of measurements isn't enough.
- If your doctor asks you to record your standing blood pressure, wait at least two minutes after standing to record your blood pressure.
- Take morning measurements before breakfast and before taking any medicines.
- Take evening measurements before going to bed and after taking any medicines.
- Record any obvious reasons for variations. These might include being unwell, drinking caffeine, smoking, a poor night's sleep and recent exercise.
Your blood pressure changes throughout the day depending on the time of day, what you're doing and any stress or excitement you're feeling. Fluctuations in blood pressure are normal. Caffeine and tobacco smoke can increase your blood pressure. It's best to take your measurements before or at least 30 minutes after drinking caffeine or smoking.
Recording your blood pressure
Some blood pressure monitors can record your blood pressure readings. But you may prefer to keep a paper diary or use a blood pressure app to record your blood pressure measurements.
Things to avoid
- Avoid measuring your blood pressure when you're uncomfortable, stressed or in pain. Or, if you're affected by extremes in temperature, such as a poorly heated home during winter.
- Some people with raised blood pressure may become anxious due to continually high readings. These feelings of anxiety can affect your blood pressure measurements. Talk to your GP if this happens to you.
- Some people may become obsessed with their blood pressure and take an excessive number of recordings. Talk to your GP if this happens to you.
Blood pressure apps
Avoid blood pressure apps that claim to be able to measure blood pressure without using a blood pressure cuff. These apps aren't validated and aren't recommended for diagnosing or managing high blood pressure.
Changing your medication
Don't change your blood pressure medications based on your blood pressure readings without talking to your GP.
HealthInfo recommends the following pages
- British and Irish Hypertension Society – BP monitors
An independent peer-reviewed list of blood pressure monitors.
- Choice – How to buy the best blood pressure monitor
Advice about buying a blood pressure monitor from the Australian consumer advocacy group.
On the next page: Medicines for lowering blood pressure
Content shared between HealthInfo Canterbury, KidsHealth and Health Navigator NZ as part of a National Health Content Hub collaborative. Last reviewed December 2021.
SourcesReview key: HIHBP-25277
