About high blood pressure

About 3 in 10 adults in the UK have high blood pressure. It’s much more common in older people – 7 out of 10 people over 75 have high blood pressure.

Symptoms of high blood pressure

Most people with high blood pressure don’t have any symptoms.

If you have very high blood pressure, or your blood pressure rises quickly, you may have headaches, problems with your vision, fits or blackouts.

Complications of high blood pressure

If you have high blood pressure, you have an increased risk of major illnesses including:

  • cardiovascular disease – such as angina (chest pain caused by reduced coronary artery blood flow), heart attack, heart failure or atrial fibrillation (irregular heart beat)
  • cerebrovascular disease – such as Transient Ischaemic Attack (TIA – sometimes called “mini stroke”), or stroke.
  • kidney damage
  • damaged sight

Causes of high blood pressure

Primary hypertension

More than 9 in 10 people with high blood pressure have what is called primary or essential hypertension. This means that it has no single clear cause.

Many factors to do with your lifestyle may contribute to primary hypertension. These include:

  • smoking
  • obesity
  • drinking a lot of alcohol – especially if you binge drink
  • lack of exercise
  • diet

If someone else in your family has high blood pressure, you also have a higher risk of developing it.

Secondary hypertension

Around 1 in 10 people with high blood pressure have secondary hypertension. This means your doctor can link your high blood pressure to a known cause:

  • kidney disease
  • endocrine disease (hormone disorders – a hormone is a regulatory chemical that occurs naturally in your body)
  •  narrowing of the arteries leading to the kidneys, or narrowing of the aorta (the largest artery leading from the heart) 

Secondary hypertension can also be caused by:

  • steroid medicines
  • the contraceptive pill
  • pregnancy, which can cause pre-eclampsia – this can be serious and harm your baby

Diagnosis of high blood pressure

You may not have any symptoms, so your GP may diagnose high blood pressure when he or she takes your blood pressure as part of a medical examination. That’s one good reason to have a regular check-up with your GP, especially if you’re over 40.

The lower your blood pressure, the better for your health. Your blood pressure should be kept below 140/85. If you have diabetes, cerebrovascular disease or cardiovascular disease, your blood pressure should be lower than this – ideally less than 130/80.

You may also need some tests to see if high blood pressure is affecting the rest of your body. These may include:

  • a urine test – protein in your urine may be the first sign of a kidney problem
  • a blood test to check your cholesterol and blood sugar levels, as well as the condition of your kidneys
  • an electrocardiogram (ECG) – a test that measures the electrical activity of your heart to see how well it’s working


You may be offered 24 hour BP monitoring at home if your GP thinks you may get ‘white coat’ hypertension – high blood pressure when a doctor or nurse measures it. A monitoring device is strapped round your waist and attached to a cuff wrapped around your upper arm. The cuff inflates and deflates automatically throughout the 24 hours and takes recordings of your blood pressure.

You might consider getting a blood pressure monitor to use yourself at home – discuss this with your GP. The British Hypertension Society  lists clinically validated blood pressure monitors. A particularly good one is this one.

It’s important to take readings at different times throughout the day, and on different days . You shouldn’t measure your blood pressure when you feel stressed. Set days in the week to take the measurement so that you can get a consistent reading.

On each occasion take three readings, about one minute apart, when lying flat and feeling relaxed. The reason for taking s number of readings is that one often sees an “alerting response” on first measuring blood pressure. This settles when you take further readings. So, record the lowest reading you get.

Treatment of high blood pressure

You’re likely to need long-term treatment for high blood pressure because it can’t usually be cured.

If you have very high blood pressure, you may need to go to hospital for treatment. But it’s much more likely that your GP and/or a nurse will look after you.


Various lifestyle changes can help. For example:

  • stop smoking
  • change your diet to a low-fat, low-salt diet that includes fruit and vegetables
  • cut down on alcohol
  • cut down on coffee and high-caffeine drinks, such as cola
  • take some regular, moderate exercise
  • lose any excess weight

It may also help to try to reduce the stress in your life to prevent short-term rises in blood pressure – try relaxation techniques or meditation.


If your blood pressure stays high, your GP may prescribe one or more of the following antihypertensive medicines.

  • ACE inhibitors (eg Ramipril)
  • Angiotensin-II receptor antagonists (eg Candesartan)
  • Calcium-channel blockers (eg Amlodipine)

If your BP don’t improve, then your GP may prescribe one of the following:

  • Alpha-blockers (eg Doxazosin)
  • Thiazide diuretic such as Bendroflumethiazide or Indapamide

If your BP still remains high your GP may refer you to a hypertension specialist at the hospital.

Special considerations of high blood pressure


If you’re pregnant your blood pressure is monitored regularly, whether you have hypertension or not. Long-term high blood pressure may be picked up at an antenatal appointment. It’s also possible that you may develop high blood pressure during your pregnancy (gestational hypertension). High blood pressure that develops after 20 weeks of pregnancy can mean you have pre-eclampsia, which can be harmful for you and your baby.

If you have high blood pressure and think you may be, or are trying to become pregnant, it’s important that you tell your GP. Certain medicines for treating high blood pressure aren’t suitable for pregnant women.

Ethnic groups

If you’re of African-Caribbean origin, you’re at a higher risk of hypertension and you should visit your GP for regular monitoring.

You should also be monitored regularly if you’re of South Asian origin because you have a higher risk of developing heart disease and diabetes.