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What is high blood pressure?
Why does it increase your risk of stroke?
How do I know if I have high blood pressure?
What can I do if I have it?
Find out more

High blood pressure is one of the biggest risk factors for stroke. It usually has no symptoms but is a contributing factor in around half of all strokes. 

What is high blood pressure?

Blood pressure is the measure of how strongly the blood presses against the walls of your arteries when your heart beats. Having high blood pressure (also known as hypertension) means that this measurement is consistently too high over a period of time.  

Am I at risk of high blood pressure?

Some things make you more likely to have high blood pressure. 

Your risk increases with age, so it's a good idea to get a blood pressure check if you are over 40.

A family history of high blood pressure can mean you have a higher risk. Black people can be more likely to have high blood pressure.

Lifestyle factors like eating too much salt, being inactive or overweight, smoking and drinking large amounts of alcohol can raise your risk.

Some health conditions can make high blood pressure more likely, so if you have diabetes, kidney disease, or obstructive sleep apnoea (interrupted breathing during sleep) you should have regular blood pressure checks.

How is high blood pressure diagnosed? 

High blood pressure does not have any symptoms, so the only way to know if you have it is to have your blood pressure measured regularly. This can be done by your GP or nurse. Some GP surgeries and pharmacies have self-testing machines you can use.

If you have had a blood pressure reading that's higher than it should be, you'll be advised to speak to a GP or nurse. It's important to go, because you might need another blood pressure test.

You can't be diagnosed with high blood pressure on a single reading. But if you visit your GP they can reassure you, and give treatment if you need it. They can also give advice on managing your blood pressure and reducing your risk of a stroke. 

How is it treated?

Most people with high blood pressure will need to take medication to reduce it. But making changes to your lifestyle such as being active and having a healthy diet can also help. 

Sticking to your medication can help you to stay healthy and reduce your risk of a stroke. Some people need to take more than one medication to control their blood pressure, and you may need to try several different types before you find the ones that suit you best. Your GP and pharmacist can give support and advice.

See below to find out more about what to do if you are diagnosed with high blood pressure. 

Why does it increase your risk of stroke?

High blood pressure puts an extra strain on all the blood vessels in your body. This can make a stroke due to a clot (ischaemic stroke) more likely, because high blood pressure damages your blood vessels and makes them become stiffer and more narrow. This can lead to clots forming and travelling to the brain, causing a stroke.

High blood pressure can also make a stroke due to a bleed (haemorrhagic stroke) more likely. One way this can happen is if you have an aneurysm (weakened blood vessel) in your brain. If this is damaged over time by high blood pressure, it can leak or burst, causing a bleed in the brain.  

Find out more

You can find much more information including what to do if you're diagnosed, and how to stay healthy with high blood pressure, in our guide: 

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