High blood pressure

A doctor straps a blood pressure monitor onto a man

High blood pressure isn’t usually something that you can feel or notice, but if you have it you’re more likely to develop coronary heart disease or have a stroke.

As many as 7 million people in the UK are living with undiagnosed high blood pressure, without knowing they are at risk.

The only way to know whether you have high blood pressure is to have it measured.

Everyone should know their blood pressure. We recommend that everyone over 40 gets their blood pressure taken by a nurse or doctor as part of a health check to assess their risk for getting cardiovascular disease.


What is blood pressure?

Put simply, blood pressure is the pressure of blood in your arteries  - the vessels that carry your blood from your heart to your brain and the rest of your body. You need a certain amount of pressure to get the blood round your body.

The pressure of the blood flowing through your arteries changes as your heart beats. The pressure in your arteries will be at its highest when your heart is contracting and pumping blood around your body and lowest as it relaxes while it fills with blood before pumping again.

Find out more about how your heart works

What is high blood pressure?

High blood pressure – or hypertension – means that your blood pressure is consistently higher than the recommended level. High blood pressure is not usually something that you can feel or notice, but over time if it is not treated, your heart may become enlarged making your heart pump less effectively.  This can lead to heart failure.

Having high blood pressure increases your chance of having a heart attack or stroke.

There isn’t always an explanation for the cause of high blood pressure, but these can play a part:

Even if you don't have high blood pressure, making some simple lifestyle changes may help prevent you developing it in the future.

How does my GP know I have high blood pressure?

Your doctor or nurse will take your blood pressure. If your blood pressure is 140/90mmHg or higher you will probably have to have this rechecked several times.

Everyone's blood pressure varies during the day. Some people have a condition known as ‘white coat hypertension’ or ‘white coat syndrome’. This is a condition where your blood pressure rises only because someone is taking your blood pressure, and not because you have an underlying medical problem.

If you have white coat hypertension, your blood pressure will return to normal when your doctor or nurse stops taking it. It can be very difficult to diagnose and this is why you may need to have your blood pressure rechecked several times, or you may be sent home with a 24 hour blood pressure monitor.

What do the numbers mean?

Every blood pressure reading consists of two numbers or measurements. They are shown as one number on top of the other and measured in mmHg, which means millimetres of mercury.  If your reading is 120/80mmHg, you might hear your doctor or nurse saying your blood pressure is "120 over 80".

The first (or top) number represents the highest level your blood pressure reaches when your heart contracts and pumps blood through your arteries - your systolic blood pressure. An example might be 130mmHg.

The second (or bottom) number represents the lowest level your blood pressure reaches as your heart relaxes between beats - your diastolic blood pressure. An example might be 75mmHg.

Unless your doctor tells you otherwise, your blood pressure should be below 140/90mmHg.  If you have heart or circulatory disease, including being told you have coronary heart disease, angina, heart attack or stroke, or have diabetes or kidney disease, then it is usually recommended that your blood pressure should be below 130/80mmHg.

What can I do to reduce my blood pressure?

If your doctor or nurse says you have high blood pressure, they are likely to encourage you to make some lifestyle changes to help reduce it. This may include increasing your physical activity, losing weight, reducing the salt in your diet, cutting down on alcohol and eating a balanced, healthy diet.

If your blood pressure is very high or these lifestyle changes do not reduce it enough, your doctor is likely to prescribe you medication to control it and to reduce your risk of having a heart attack or stroke.

If you are already being treated for high blood pressure and have any concerns about it, you should make an appointment with your GP. Do not stop taking your medication unless your GP tells you to.


Want to find out more?

Stroke - your quick guide

order now Order now Order now