Learn about your blood pressure

How is blood pressure measured?

Blood pressure readings are written as two numbers (e.g., 120/80 mmHg).

Systolic pressure (the first number) measures the highest level of your blood pressure – when your heart beats and pumps blood through your arteries.

Diastolic pressure (the second number) measures the lowest level of your blood pressure – when your heart relaxes between beats.

Both numbers are measured in mmHg (millimetres of mercury).

A normal blood pressure is usually between 90/60 mmHg and 120/80 mmHg.

Measuring your blood pressure

Watch this video to learn how to measure your blood pressure accurately.

What do my blood pressure numbers mean?

You can use this guide to understand your reading and what you need to do:

Low blood pressure (below 90/60mmHg)

If your blood pressure is below 90/60mmHg, you may have low blood pressure. Drinking water can help improve low blood pressure. Visit your GP if you also have other signs of low blood pressure like dizziness and fainting.

Healthy or normal blood pressure (between 90/60mmHg and 120/80mmHg)

If your blood pressure is within these ranges, you have healthy blood pressure. It is important to check your blood pressure at regular intervals to make sure it’s normal.

High normal blood pressure (between 120/80mmHg and 140/90mmHg)

If your blood pressure is within these ranges, you have slightly raised blood pressure. Re-check blood pressure within a few months and speak to your doctor if you’re concerned.

High blood pressure (over 140/90mmHg)

If your blood pressure is over 140/90mmHg, you may have high blood pressure. You should make an appointment with your doctor to discuss this and think about any changes you could make to bring it down.

We have more information about the different stages of high blood pressure.