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High blood pressure

A doctor straps a blood pressure monitor onto a man

Having high blood pressure increases your risk of heart attack and stroke, so knowing your blood pressure could save your life. 

What is blood pressure?

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 moving round your body.

Your blood pressure naturally goes up and down throughout the day and night, and it’s normal for it to go up while you’re moving about. It’s when your overall blood pressure is consistently high, even when you are resting, that you need to do something about it.

What is high blood pressure (hypertension)?  


High blood pressure is medically known as hypertension. It means your blood pressure is consistently too high and means that your heart has to work harder to pump blood around your body. High blood pressure is serious. If you ignore it, it can lead to heart and circulatory diseases like heart attack or stroke. It can also cause kidney failure, heart failure, problems with your sight and vascular dementia.

Although your arteries are stretchy to cope with your blood pressure going up and down, if you have high blood pressure, your arteries lose their stretchiness and become stiff or narrow. The narrowing makes it easier for fatty material (atheroma) to clog them up. 

What causes high blood pressure image

If the arteries that carry blood to your heart get damaged and clogged, it can lead to a heart attack. If this happens in the arteries that carry blood to your brain it can lead to a stroke.

Around 50% of heart attacks and strokes are associated with high blood pressureWhat causes high blood pressure?

There isn’t always an explanation for the cause of high blood pressure, but most people develop high blood pressure because of their diet, lifestyle or medical condition.

Sometimes high blood pressure runs in families and can also worsen with age. People living in deprived areas are at higher risk of having high blood pressure, and it is also more common if you are of black African or black Caribbean descent. Even in these cases, you may still be able to improve your blood pressure by changing your diet and being active.

These can all increase your risk of getting high blood pressure:

In a very small number of people, the cause of high blood pressure can be identified. Doctors sometimes call this secondary hypertension. For example, an abnormal production of hormones from the adrenal glands can lead to high blood pressure. If your doctor gives you treatment for the hormonal condition, your blood pressure should then return to normal.

Other causes of secondary hypertension include:

  • kidney disease
  • diabetes, and
  • some medicines, such as oral contraceptives and some over-the-counter and herbal medicines.

If you are concerned that any medicine or remedy might affect your blood pressure, ask your doctor or pharmacist about it.

Visit the NHS website for more information about the causes of secondary hypertension.

Symptoms of high blood pressure

High blood pressure rarely has noticeable symptoms. That's why it's so important to get your blood pressure checked. Find out more about the symptoms of high blood pressure.

How is blood pressure measured?

Your blood pressure is usually measured using a sphygmomanometer (pronounced ‘svig-mo-man-ometer’). This is usually a digital electronic monitor, which is connected to an inflatable cuff that is wrapped around your upper arm.

When you have your blood pressure measured, the reading is written as two numbers. The first is when the pressure is at its highest (or systolic pressure), and the second at its lowest (or diastolic pressure). For example, your reading will be something like: 140/90 mmHg (mmHg is a unit for measuring blood pressure). You’ll be told something like ‘140 over 90’.

Systolic pressure: This is the highest level of your blood pressure – when your heart beats and contracts to pump blood through your arteries.

Diastolic pressure: This is the lowest level of your blood pressure – when your heart relaxes between beats.

Where can I get my blood pressure measured or tested?

You can get your blood pressure checked at:

As many as 5 million adults in the UK have undiagnosed high blood pressure, so will not know that they are at risk. The only way to know whether you have high blood pressure is to have it measured. So, it’s important to get your blood pressure checked.

What is a healthy or normal blood pressure?

Your blood pressure should be under 140/90 mmHg.


  • Systolic: lower than 90 mmHg
  • Diastolic: lower than 60 mmHg

Find out more about low blood pressure.


  • Systolic: lower than 140 mmHg
  • Diastolic: lower than 90 mmHg

Possible hypertension

  • Systolic: between 140 and 180 mmHg
  • Diastolic: between 90 and 110 mmHg

Further checks such as home monitoring or ABPM would normally be needed to make a diagnosis of hypertension.

Severe hypertension

  • Systolic: higher than 180 mmHg
  • Diastolic: higher than 110 mmHg

Medications and treatments for high blood pressure

If your blood pressure is considered to be high or very high, your doctor will offer you medicines to help lower your blood pressure. Find out more about medications and treatment for high blood pressure.

Help and support

If you have high blood pressure, it's important to know that you're not alone. It’s important to find support from the people around you and healthcare professionals. Make sure you check your blood pressure and keep a diary of your readings regularly, so you can see your progress.

Join our HealthUnlocked community.

Call our Heart Helpline at 0300 330 3311 to speak to one of our Cardiac Nurses. They can give you information and support about heart and circulatory diseases, and their risk factors. 


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