High blood pressure
High blood pressure, also known as hypertension, is the most important known risk factor for stroke.
Blood pressure is a measure of the force with which blood presses on the walls of your arteries as it is pumped around your body. This pumping action is driven by your heart.
Normal blood pressure is around 120/80. If your blood pressure is regularly over 140/90, you have high blood pressure.
High blood pressure puts a strain on blood vessels all over the body, including the arteries that lead to the brain. This means the heart has to work much harder to keep the blood circulation going.
High blood pressure can lead to a stroke in several ways:
- It damages blood vessel walls and makes them weaker.
- It can speed up common forms of heart disease.
- It can cause blood clots or plaques to break off artery walls and block a brain artery.
The higher the blood pressure, the greater the stroke risk.
What causes high blood pressure?
In most cases it is impossible to pinpoint an exact cause. However, there are a number of risk factors that have been linked to high blood pressure. These include:
- A family history of high blood pressure
- Age (blood pressure can rise as people get older)
- Men are more likely to have high blood pressure than women
- Being overweight
- Excessive alcohol drinking
- Smoking
- Diabetes
- Lack of exercise
- A diet high in salt.
Control your risk
Know your blood pressure and keep it down. Your doctor can help you to regularly check your blood pressure.
You can control your blood pressure by changing your diet and lifestyle, particularly through regular exercise and maintaining a healthy weight.
Everyone who has had a stroke should be on blood pressure lowering medication. This is even if you have ‘normal’ blood pressure.
The lower your blood pressure, the lower your risk of stroke.
More information
High Blood Pressure and Stroke Fact Sheet (pdf)
How to Guide - Reading Your Blood Pressure (pdf)
Your doctor will usually be the one to ask you to measure your blood pressure at home. When measuring at home, it's important to use an approved device that has been tested for accuracy.