Heart test
Ambulatory Blood Pressure Monitoring
This test measures your blood pressure automatically over 24 hours as you go about your day, giving a truer picture than a single reading in clinic.
Quick answer
Ambulatory Blood Pressure Monitoring: what it is and what the results mean
Ambulatory blood pressure monitoring (ABPM) uses a small cuff and monitor worn for about 24 hours, taking readings at intervals during normal activity and sleep to show how blood pressure changes over a day.
- Why it is done: It is used to confirm a diagnosis of high blood pressure, to check for "white coat" effect (higher readings in clinic), to assess control on treatment, and to see how pressure behaves overnight.
- Understanding results: The many readings give an average and a pattern across the day and night, which is more reliable than a single measurement.
What it is
Ambulatory blood pressure monitoring (ABPM) uses a small cuff and monitor worn for about 24 hours, taking readings at intervals during normal activity and sleep to show how blood pressure changes over a day.
Why it is done
It is used to confirm a diagnosis of high blood pressure, to check for "white coat" effect (higher readings in clinic), to assess control on treatment, and to see how pressure behaves overnight.
What to expect
A cuff is fitted to your upper arm and connected to a monitor worn on a belt. It inflates automatically at set times, including at night. You keep a brief diary and return the device the next day.
Understanding the results
The many readings give an average and a pattern across the day and night, which is more reliable than a single measurement. This helps decide whether treatment is needed and how well it is working.
Good to know
Risks and limitations
The test is safe; the repeated cuff inflation can be mildly uncomfortable and may disturb sleep a little. Very active movement can occasionally interfere with individual readings, but the overall pattern remains useful.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Ambulatory Blood Pressure Monitoring: frequently asked questions
Why measure blood pressure over 24 hours?
A single clinic reading can be misleadingly high or low. Measuring over 24 hours gives an average and shows how pressure changes with activity and sleep, giving a more accurate basis for diagnosis and treatment.
Can I sleep with the blood pressure monitor on?
Yes, you wear it overnight so night-time readings can be recorded. The cuff inflating may briefly wake you, but this is expected and the overnight readings are a useful part of the test.
Related tests
Other heart test investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- UK National Screening Committee / relevant professional body
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