Overview

High blood pressure, or hypertension, rarely has noticeable symptoms. But if untreated, it increases your risk of serious problems such as heart attacks and strokes.

The only way to find out if your blood pressure is high is to have your blood pressure checked

Title
High blood pressure

Causes

In about 1 in 20 cases, high blood pressure occurs as the result of an underlying condition, medication or drug.

Conditions that can cause high blood pressure include:

Medicines and drugs that can increase your blood pressure include:

In these cases, your blood pressure may return to normal once you stop taking the medicine or drug.

Diagnosis

High blood pressure (hypertension) doesn't usually have any symptoms, so the only way to find out if you have it is to get your blood pressure checked.

Healthy adults aged over 40 should have their blood pressure checked at least once every five years.

If you're at an increased risk of high blood pressure, you should have your blood pressure checked more often – ideally once a year.

Having this done is easy and could save your life.

Where to get a blood pressure test

You can ask for a blood pressure check – you don't have to wait to be offered one.

Blood pressure testing is available:

  • at your GP surgery – by a GP, practice nurse, healthcare assistant or self-service machine
  • at some pharmacies
  • at an NHS Health Check appointment offered to adults aged 40-74 in England
  • in some workplaces
  • at a health event

You can also test your blood pressure at home using a home testing kit.

The test

A stethoscope, arm cuff, pump and dial was normally used to measure your blood pressure, but automatic devices with sensors and digital displays are commonly used nowadays.

It's best to sit down with your back supported and legs uncrossed for at least five minutes before the test.

You'll usually need to roll up your sleeves or remove any long-sleeved clothing so the cuff can be placed around your upper arm. Try to relax and avoid talking while the test is carried out.

During the test:

  • you hold out one of your arms so it's at the same level as your heart, and the cuff is placed around it – your arm should be supported in this position with a cushion or the arm of a chair, for example
  • the cuff is pumped up to restrict the blood flow in your arm – this squeezing may feel a bit uncomfortable, but only lasts a few seconds
  • the pressure in the cuff is slowly released and detectors sense vibrations in your arteries – a doctor will use a stethoscope to detect these if your blood pressure is measured manually
  • the pressure in the cuff is recorded at two points as the blood flow starts to return to your arm – these measurements are used to give your blood pressure reading

You can usually find out your result straight away, either from the healthcare professional carrying out the test or on the digital display.

If your blood pressure is high, you may be advised to record your blood pressure at home to confirm whether you have high blood pressure.

Ambulatory (24-hour) monitoring

Having a raised blood pressure reading in one test doesn't necessarily mean you have high blood pressure.

Blood pressure can fluctuate throughout the day. Feeling anxious or stressed when you visit your GP can also raise your blood pressure.

If you have a high reading, you may be asked to take some readings with a home blood pressure monitor or wear a 24-hour monitor that checks your blood pressure throughout the day. This will confirm whether you have consistently high blood pressure.

This is known as 24-hour or ambulatory blood pressure monitoring (ABPM).

Home testing

Blood pressure tests can also be carried out at home using your own digital blood pressure monitor.

Like 24-hour or ambulatory monitoring, this can give a better reflection of your blood pressure. It can also allow you to monitor your condition more easily in the long term.

You can buy a variety of low-cost monitors so you can test your blood pressure at home or while you're out and about.

It's important to make sure you use equipment that has been properly tested. The British Hypertension Society (BHS) has information about validated blood pressure monitors that are available to buy.

Understanding your blood pressure reading

Blood pressure is measured in millimetres of mercury (mmHg) and is given as two figures:

  • systolic pressure – the pressure when your heart pushes blood out
  • diastolic pressure – the pressure when your heart rests between beats

For example, if 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.

As a general guide:

  • high blood pressure is considered to be 140/90mmHg or higher (or an average of 135/85mmHg at home)
  • ideal blood pressure is considered to be between 90/60mmHg and 120/80mmHg
  • low blood pressure is considered to be 90/60mmHg or lower

A blood pressure reading between 120/80mmHg and 140/90mmHg could mean you're at risk of developing high blood pressure if you don't take steps to keep your blood pressure under control.

Treatment

Simple lifestyle changes can often help reduce high blood pressure (hypertension), although some people may need to take medication as well.

Your GP can advise you about changes you can make to your lifestyle and discuss whether they think you would benefit from medication.When treatment is recommended

Everyone with high blood pressure is advised to make healthy lifestyle changes.

Whether medication is recommended depends on your blood pressure reading and your risk of developing problems such as heart attacks or strokes.

Your doctor will carry out some blood and urine tests, and ask questions about your health to determine your risk of other problems:

  • if your blood pressure is consistently above 140/90mmHg (or 135/85mmHg at home) but your risk of other problems is low – you'll be advised to make some changes to your lifestyle
  • if your blood pressure is consistently above 140/90mmHg (or 135/85mmHg at home) and your risk of other problems is high – you'll be offered medication to lower your blood pressure, in addition to lifestyle changes
  • if your blood pressure is consistently above 160/100mmHg – you'll be offered medication to lower your blood pressure, in addition to lifestyle changes
Lifestyle changes

There are some changes you could make to your lifestyle to reduce high blood pressure. Some of these will lower your blood pressure in a matter of weeks, while others may take longer.

These include:

You can take these steps today, regardless of whether or not you're taking blood pressure medication. In fact, by making these changes early on you may be able to avoid needing medication.

Read more advice about lifestyle changes to prevent and reduce high blood pressure.

Medication for high blood pressure

Several medications can be used to help control high blood pressure. Many people need to take a combination of different medicines.

The medication recommended for you at first will depend on your age and ethnicity:

  • if you're under 55 years of age – you'll usually be offered an ACE inhibitor or an angiotensin-2 receptor blocker (ARB)
  • if you're aged 55 or older, or you're any age and of African or Caribbean origin – you'll usually be offered a calcium channel blocker

You may need to take blood pressure medication for the rest of your life. But your doctor might be able to reduce or stop your treatment if your blood pressure stays under control for several years.

It's really important to take your medications as directed. If you miss doses, it won't work as effectively. The medication won't necessarily make you feel any different, but this doesn't mean it's not working.

Medications used to treat high blood pressure can have side effects, but most people don't experience any. If you do, changing medication will often help.

ACE inhibitors

Angiotensin-converting enzyme (ACE) inhibitors reduce blood pressure by relaxing your blood vessels.

Common examples are enalapril, lisinopril, perindopril and ramipril.

The most common side effect is a persistent dry cough. Other possible side effects include headaches, dizziness and a rash.

Angiotensin-2 receptor blockers (ARBs)

ARBs work in a similar way to ACE inhibitors. They're often recommended if ACE inhibitors cause troublesome side effects.

Common examples are candesartan, irbesartan, losartan, valsartan and olmesartan.

Possible side effects include dizziness, headaches, and cold or flu-like symptoms.

Calcium channel blockers

Calcium channel blockers reduce blood pressure by widening your blood vessels.

Common examples are amlodipine, felodipine and nifedipine. Other medicines such as diltiazem and verapamil are also available.

Possible side effects include headaches, swollen ankles and constipation.

Drinking grapefruit juice while taking some calcium channel blockers can increase your risk of side effects.

Diuretics

Sometimes known as water pills, diuretics work by flushing excess water and salt from the body through urine. They're often used if calcium channel blockers cause troublesome side effects.

Common examples are indapamide and bendroflumethiazide.

Possible side effects include dizziness when standing up, increased thirst, needing to go to the toilet frequently, and a rash.

Low potassium level (hypokalaemia) and low sodium level (hyponatraemia) may also be seen after long-term use.

Beta-blockers

Beta-blockers can reduce blood pressure by making your heart beat more slowly and with less force.

They used to be a popular treatment for high blood pressure, but now only tend to be used when other treatments haven't worked.

This is because beta-blockers are considered less effective than other blood pressure medications.

Common examples are atenolol and bisoprolol.

Possible side effects include dizziness, headaches, tiredness, and cold hands and feet.

Prevention

High blood pressure can often be prevented or reduced by eating healthily, maintaining a healthy weight, taking regular exercise, drinking alcohol in moderation and not smoking.

Healthy diet

Cut down on the amount of salt in your food and eat plenty of fruit and vegetables. The Eatwell Guide highlights the different types of food that make up our diet, and shows the proportions we should eat them in to have a well-balanced and healthy diet.

Salt raises your blood pressure. The more salt you eat, the higher your blood pressure. Aim to eat less than 6g (0.2oz) of salt a day, which is about a teaspoonful.

Eating a low-fat diet that includes lots of fibre – such as wholegrain rice, bread and pasta – and plenty of fruit and vegetables also helps lower blood pressure. Aim to eat five portions of fruit and vegetables every day.

Limit your alcohol intake

Regularly drinking alcohol above recommended limits can raise your blood pressure over time.

Staying within these recommended levels is the best way to reduce your risk of developing high blood pressure:

  • men and women are advised not to regularly drink more than 14 units a week
  • spread your drinking over three days or more if you drink as much as 14 units a week

Alcohol is also high in calories, which will make you gain weight and can further increase your blood pressure.

Lose weight

Being overweight forces your heart to work harder to pump blood around your body, which can raise your blood pressure.

Find out if you need to lose weight with the BMI healthy weight calculator.

If you do need to shed some weight, it's worth remembering that just losing a few pounds will make a big difference to your blood pressure and overall health.

Get tips on losing weight safely.

Get active

Being active and taking regular exercise lowers blood pressure by keeping your heart and blood vessels in good condition.

Regular exercise can also help you lose weight, which will also help lower your blood pressure.

Adults should do at least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity such as cycling or fast walking every week.

Physical activity can include anything from sport to walking and gardening. Get more ideas on how to get active.

Cut down on caffeine

Drinking more than four cups of coffee a day may increase your blood pressure.

If you're a big fan of coffee, tea or other caffeine-rich drinks, such as cola and some energy drinks, consider cutting down.

It's fine to drink tea and coffee as part of a balanced diet, but it's important that these drinks are not your main or only source of fluid.

Stop smoking

Smoking doesn't directly cause high blood pressure, but it puts you at much higher risk of a heart attack and stroke.

Smoking, like high blood pressure, will cause your arteries to narrow. If you smoke and have high blood pressure, your arteries will narrow much more quickly, and your risk of heart or lung disease in the future is dramatically increased.

Get help to stop smoking.

Get a good night's sleep

Long-term sleep deprivation is associated with a rise in blood pressure and an increased risk of hypertension. It's a good idea to try to get at least six hours of sleep a night if you can.

Risks

Factors that can raise your risk of developing high blood pressure include:

  • age – the risk of developing high blood pressure increases as you get older
  • a family history of high blood pressure
  • being of African or Caribbean origin
  • a high amount of salt in your food
  • a lack of exercise
  • being overweight or obese
  • regularly drinking large amounts of alcohol
  • smoking
  • long-term sleep deprivation

Making healthy lifestyle changes can help keep your blood pressure at a normal level.