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Understanding your blood pressure reading

Having good blood pressure is possibly the most important factor in cutting your risk of a heart attack, stroke or diabetes complications. Find out about what your blood pressure should be.

There are two readings taken to see if your blood pressure is normal, high or low.

Everyone over 40 should have their blood pressure checked at least once every five years, but if you have diabetes or non-diabetic hyperglycaemia (NDH or prediabetes), checking your blood pressure is a key part of your annual review.

How blood pressure is measured

A blood pressure test is done in a number of places including your GP, some chemists, an NHS Health Check or even at work. You can even test your blood pressure at home with a home testing kit.

A stethoscope, pump, arm cuff and dial are often used, but sensors and digital displays can also measure blood pressure.

Your blood pressure is measured in millimetres of mercury (mmHg) and two figures are given:

  1. Systolic pressure, which is the pressure when your heart pushes blood out.
  2. Diastolic pressure, which is the pressure when your heart rests between beats.

So a reading of 140/90mmHg means you have a systolic pressure of 140mmHg and a diastolic pressure of 90mmHg.

What your blood pressure should be

An ideal blood pressure is between 90/60mmHg and 120/80mmHg.

Your blood pressure is low if it is less than 90/60mmHg.

With diabetes, you have high blood pressure if your reading is 140/80mmHg or higher (or an average of 135/75mmHg at home).

If you have diabetes, the normal guidelines about blood pressure are different because of the way that the risks of diabetes and blood pressure combine together.

If you’re younger or if you have complications, there is an additional long-term benefit from getting your blood pressure below 130/80 in order to avoid the damage that high blood pressure can cause.

You may need treatment to keep your blood pressure under control. This is called antihypertensive medication.

However, if you are overweight, the most effective thing that you can do to help your blood pressure is to lose weight.

Even losing 5-10% of your body weight can have a dramatic effect on your blood pressure, and may even mean that you could stop taking some of your blood pressure medication (or avoid it altogether).

Find out how to be healthier.

Checking your blood pressure is high over time

Blood pressure can change throughout the day because of how we are feeling, so if you’re feeling stressed, it could be higher.

If you have a high reading, you may be asked to take some readings over a period of 24 hours, to see if it stays high during that whole time. This can be done using either a home blood pressure monitor or wearing a 24-hour monitor. This test is called 24-hour or ambulatory blood pressure monitoring (ABPM).

Find out more about programmes that will help you look after yourself.