High blood pressure (hypertension) rarely has noticeable symptoms, but if untreated it increases your risk of heart attack, heart failure, kidney disease, stroke or dementia.

Over 5 million people in England are unaware they have high blood pressure, yet it affects more than 1 in 4 adults.

The only way of knowing there is a problem is to have your blood pressure checked

All adults should have their blood pressure checked regularly (at least every five years). Having this done is easy and could save your life.

Find out more about getting a blood pressure test.

What is high blood pressure?

Your heart pumps blood around your body to deliver energy and oxygen. A certain amount of pressure in your blood vessels is needed to do this. However, if there is too much pressure in your blood vessels, it puts extra strain on your arteries and heart, which can lead to serious conditions such as heart attack, heart failure, kidney disease, stroke, or dementia.

Blood pressure is measured in millimeters 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.

    A reading over 140/90mmHg indicates high blood pressure (medically known as hypertension), which should be confirmed by tests on separate occasions to reach a diagnosis. Find out more about the diagnosis of high blood pressure.

    A blood pressure reading below 120/80mmHg is considered to be ideal.

    People with a blood pressure reading below 90/60mmHg are usually regarded as having low blood pressure.

    Who is most at risk?

    Your chances of having high blood pressure increase as you get older. There isn't always a clear cause of high blood pressure but you are at increased risk if you:

    • are aged over 65
    • 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 alcohol 
    • drink too much coffee (or other caffeine-based drinks)
    • smoke 

    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 at least 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
    • cutting down on caffeine
    • stopping smoking

    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.

    High blood pressure in pregnancy

    Symptoms and treatment of high blood pressure when you're pregnant

    Page last reviewed: 04/07/2014

    Next review due: 04/07/2016