Blood pressure: understanding your readings

What is blood pressure?

Your blood pressure is the force at which your blood pushes against the walls of your arteries as it's pumped around your body.

• If your blood pressure is too low (hypotension), it can cause you to feel dizzy or even faint.

• If your blood pressure is too high (hypertension), it can increase your chance of heart failure, heart attack, or stroke.

What causes high blood pressure?

In most cases, there isn't a specific reason for the cause of high blood pressure, but most people develop it because of their diet, lifestyle or medical condition.

Your risk increases as you age, but also if you:

• Have someone in your family with high blood pressure.

• Are someone who smokes.

• Drink too much alcohol.

• Eat too much salt and not enough fruit and vegetables.

• Don't get enough exercise.

• Are overweight or living with obesity.

High blood pressure is more common in deprived areas, and rates are higher in people who are of black African or black Caribbean descent. Changes in your diet and increasing activity levels can often help improve your blood pressure.

Can pregnancy lead to high blood pressure?

If you're pregnant, your blood pressure may rise - especially if you have a history of the condition.

If you develop high blood pressure while pregnant, a midwife specialising in pregnancy-related hypertension will evaluate your condition in a hospital.

If you're pregnant with a history of high blood pressure, see a specialist to discuss treatment. If you're on blood pressure medicine and planning a pregnancy, talk to your doctor to possibly switch treatment.

If you're already pregnant, tell your doctor immediately, as some medicines may be unsafe during pregnancy.

Checking your blood pressure

You can ask your doctor for a blood pressure check. If you're aged 40 to 74 in England, you're eligible for a blood pressure check as part of the free NHS Health Check, offered every five years.

You can get your blood pressure tested at several places for free - such as your local pharmacy, or your registered medical practice. You can also take it at home with your own blood pressure monitor.

If you are buying a blood pressure monitor to use at home, choose one that has been accredited by the British and Irish Hypertension Society (BIHS). This means your monitor has been tested to ensure its accuracy. For a list of validated blood pressure monitors, visit the BIHS website.

Monitors usually cost around £20 - £100. You can buy BHIS-accredited blood pressure monitors directly from the BHF. Please can we add: What’s more, profits help support BHF fund lifesaving research.

If your blood pressure is usually healthy, check it every 6 months or so using an approved home monitor.

How to read your blood pressure numbers

Blood pressure machines usually include an arm cuff to measure your blood pressure. This is wrapped around your upper arm and inflated until tight - automatic devices use sensors in the cuff to display results digitally. A healthcare professional may also use a stethoscope.

A blood pressure reading consistently between 120/80 - 139/89 mmHg is generally considered OK. However, it could suggest an increase in your chances of developing high blood pressure.

The stress you may feel when you have your blood pressure measured by a healthcare professional in an unusual setting - white coat syndrome - may mean your figures are inaccurate or too high. Your healthcare professional may recheck it or ask you to check it yourself at home. They may also use an ambulatory blood pressure monitor (ABPM) which tracks your blood pressure over a 24-hour period.

The NHS offers a simple tool to help you understand your blood pressure reading.

Simpler ways to help lower your high blood pressure

There are many straightforward lifestyle changes you can make to help lower your blood pressure - and keep it lower. These lifestyle changes will support any medicines you are taking and improve your overall health.

• Eat healthily - Eat plenty of fruits and vegetables - go for five a day - whole grains, and low-fat dairy. Choose foods low in cholesterol, saturated fat, and salt.

• Drink less alcohol - keep your weekly alcohol within safer limits.

• Lower your caffeine intake - have less coffee, tea, and fizzy drinks.

• Lose weight - especially if you're carrying extra weight around your waist. Aim to get your weight within a healthy BMI range.

• Exercise regularly - try to have at least 150 minutes of moderate-intensity exercise each week - for at least ten minutes a day. Find activities that you enjoy so you are more likely to keep on doing them.

• Avoid stress - do more of the things you enjoy and less of the things that trigger your stress.

• Sleep well - Get at least 7 hours a day.

• Don't smoke - stopping smoking is one of the best things you can do for your blood pressure and your overall health.

Blood pressure medicine

Your doctor may prescribe a course of treatment for high blood pressure if your readings are high at the surgery, high from your home readings, or if lifestyle changes haven't been able to lower your blood pressure if you were borderline.

The type and amount of medicines prescribed for you will be down to several factors such as how high your blood pressure is and your age.