High blood pressure (hypertension) means that your blood pressure is continually higher than the recommended level. It rarely has noticeable symptoms.
Around 30% of people in England have high blood pressure but many don't know it. If left untreated, high blood pressure increases your risk of a heart attack or stroke. It is often referred to as a "silent killer".
The only way of knowing there is a problem is to have your blood pressure measured.
All adults should have their blood pressure checked at least every five years. If you haven’t had yours measured, or you don’t know what your blood pressure reading is, ask your GP to check it for you.
What is high blood pressure?
Blood pressure is measured in millimetres of mercury (mmHg) and is recorded as two figures:
- systolic pressure – the pressure of the blood when your heart beats to pump blood out
- diastolic pressure – the pressure of the blood when your heart rests in between beats, which reflects how strongly your arteries are resisting blood flow
For example, if your GP says your blood pressure is "140 over 90", or 140/90mmHg, it means you have a systolic pressure of 140mmHg and a diastolic pressure of 90mmHg.
You are said to have high blood pressure (medically known as hypertension) if readings on separate occasions consistently show your blood pressure to be 140/90mmHg or higher.
A blood pressure reading below 130/80mmHg is considered to be normal.
Who is most at risk?
Your chances of having high blood pressure increase as you get older. There is often no clear cause of high blood pressure but you are at increased risk if you:
- are overweight
- have a relative with high blood pressure
- are of African or Caribbean descent
- eat too much salt
- don't eat enough fruit and vegetables
- don't do enough exercise
- drink too much coffee (or other caffeine-based drinks)
- drink too much alcohol
- are aged over 65
If you fall into any of the groups listed above, consider making changes to your lifestyle to lower your risk of high blood pressure. Also consider having your blood pressure checked more often, ideally about once a year.
Prevention and treatment
You can take steps to prevent high blood pressure by:
- losing weight if you need to
- reducing the amount of salt you eat
- exercising regularly
- eating a healthy diet
- cutting back if you drink too much alcohol
- stopping smoking
- cutting down on caffeine
Find out more about how to prevent high blood pressure.
If your blood pressure is found to be high, it will need to be closely monitored until it is brought under control. Your doctor will usually suggest changes to your lifestyle and, sometimes, medication to achieve this. Find out more about how blood pressure is treated.
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Page last reviewed: 04/07/2014
Next review due: 04/07/2016