24-hour blood pressure monitor (ambulatory blood pressure monitor)

A 24-hour blood pressure monitor measures your blood pressure at regular intervals over a day and night. It is also called ambulatory blood pressure monitoring (ABPM).

Your blood pressure changes throughout the day. It naturally increases with things like:

• exercise
• nicotine and caffeine
• stress
• some medications.

It lowers when you’re asleep at night.

However, if your blood pressure stays high all the time, you’re at higher risk of heart attack and stroke.

What is a 24-hour blood pressure monitor?

A 24-hour blood pressure monitor is a small device that records your blood pressure at regular intervals over a day and a night. It is also called ambulatory blood pressure monitoring (ABPM).

Why is ambulatory blood pressure monitoring used?

A 24-hour blood pressure monitor tells your doctor if your blood pressure stays high for most or all of the day and night.

It helps them decide if medication to lower your blood pressure could help reduce your heart attack and stroke risk.

If you’re already on blood pressure medication, the doctor may order this test to see if you’re taking the right amount.

Before your appointment

You won’t be able to have a bath or shower while you’re wearing the monitor, so you may want to have one beforehand.

Wear a top or shirt with loose sleeves so the blood pressure cuff will fit comfortably underneath.

What happens at the appointment?

You’ll go to the hospital, clinic or GP practice to have the cuff fitted. The initial appointment takes up to 30 minutes.

At the appointment you’ll be given a blood pressure cuff to wear on your upper arm. It is connected to a small monitor which is worn on a strap over your shoulder, or on a belt around your waist, under your clothes.

You’ll also be given a diary to record any activity and any symptoms you have while you’re wearing the monitor.

While you’re wearing the monitor

You’ll wear the monitor for 24 hours.

It measures your heart rate and blood pressure every half hour during the day and hourly at night.

During each measurement, the blood pressure cuff will inflate (tighten) and then deflate (loosen).

Try to stay still and keep your arm relaxed while the reading is being taken. Make sure the tube that attaches the cuff to the monitor isn’t twisted or bent.

Returning the monitor

You’ll need to return to the clinic the next day to have the monitor taken off.

You won’t get the results on the day. The information will be analysed and sent to the doctor who ordered the test.

Are the any risks?

There are no real risks of 24-hour blood pressure monitoring, although some people may have pain in their arm when the cuff inflates.

Some people may sleep badly because of the nighttime readings.

Key things to remember