Blood pressure

Blood pressure is the pressure of blood on the walls of your arteries as your heart pumps blood around your body. It does not stay the same all the time. It changes to meet your body’s needs, and it is normal for your blood pressure to go up and down throughout the day. It is affected by various factors, including body position, breathing, emotional state, exercise and sleep.

If blood pressure remains high over a long period of time, it can lead to a heart attack, stroke, heart failure or kidney disease.

What blood pressure numbers mean#

Blood pressure is recorded as two numbers, such as 120/80. The larger number is the pressure in the arteries as the heart pumps out blood during each beat. This is called the systolic blood pressure. The lower number is the pressure as the heart relaxes before the next beat. This is called the diastolic blood pressure. Both are measured in units called millimetres of mercury (mmHg).

What is considered a healthy blood pressure varies from person to person. Your doctor will explain your ideal blood pressure based on a range of factors, including your overall health. The following numbers should only be used as a guide:

High blood pressure usually does not have any symptoms. You can have high blood pressure and feel perfectly well. The only way to find out is to have it checked regularly by your doctor. Low blood pressure can make people feel dizzy or faint, and it can be a problem if it has a negative impact on your body or affects the way you feel. See your doctor if you think you have low blood pressure.

The medical name for high blood pressure is hypertension. The medical name for low blood pressure is hypotension.

Measuring blood pressure#

It is best to measure blood pressure when you are relaxed and sitting. Blood pressure is usually measured with an inflatable pressure cuff that wraps around your upper arm. This cuff is part of a machine called a sphygmomanometer.

Because your blood pressure changes to meet your body’s needs, a single high reading does not mean you have high blood pressure. If a reading is high, your doctor may measure your blood pressure again on several separate occasions before making a diagnosis.

Your doctor may also recommend you have your blood pressure recorded at home with a monitoring device. This is known as 24-hour ambulatory blood pressure monitoring, and it involves measuring your blood pressure at regular intervals (usually every 20–30 minutes) while you do your usual activities, including sleeping. Your doctor will organize this service if required.

If you are considering buying a blood pressure device to use at home, it is best to speak to your doctor to see if it is needed. If so, choose a device that measures blood pressure accurately and is validated for clinical use.

Getting your blood pressure checked#

Get regular blood pressure checks. Have it checked at least every two years if your blood pressure is in the healthy range and you have no other risk factors for cardiovascular disease, you have never been diagnosed with high blood pressure before, and you have no family history of high blood pressure. Your doctor can also check your blood pressure during routine visits.

You should have your blood pressure checked more frequently (such as every 12 months, or as directed by your doctor) if you have other risk factors for cardiovascular disease, such as a personal or family history of high blood pressure, or if you have previously had a heart attack or stroke.

A heart health check is a short check-up with your doctor. As part of it, your doctor will ask about your medical and family history of heart disease and your lifestyle, including your diet, physical activity, and whether you smoke or drink alcohol. They will check your blood pressure, cholesterol and blood sugar levels, then use this information to estimate your risk of having a heart attack or stroke over the coming years, and discuss how you can lower your risk.

High blood pressure and your overall risk#

If your blood pressure remains high, it can lead to serious conditions like a heart attack, heart failure, stroke or kidney disease. Your risk depends on the other risk factors you might have. Modifiable risk factors are ones you can change. Non-modifiable risk factors are ones you can’t change.

Heart attack and stroke risk factors that you can change include:

• tobacco smoking
• poor diet
• physical inactivity
• being overweight or obese
• alcohol intake
• high cholesterol
• high blood pressure (hypertension)
• type 2 diabetes
• depression and anxiety
• social isolation

Risk factors you can’t change include:

• your age
• whether you were born male or female (your sex)
• being post-menopausal
• a premature family history of heart disease – if an immediate family member (such as a parent or sibling) has had a heart attack or stroke before the age of 65, mention this to your doctor
• belonging to an ethnic background with higher cardiovascular risk

Your doctor will support you to make changes to manage your blood pressure, and may also recommend medicines. Even if you need to take medicines, it’s still important to make healthy changes too.

Quit smoking#

Tobacco smoking is a major risk factor for heart disease and can increase blood pressure. Stopping smoking is one of the best things you can do to help manage your blood pressure. Every cigarette you don’t smoke is doing you good.

The most effective way to stop smoking is with a combination of support and stop-smoking medicines such as nicotine replacement therapy. There is also evidence that e-cigarettes can increase heart rate and blood pressure, which may increase the risk of heart disease.

If you are ready to quit, or thinking about it, talk to your doctor about ways to help you give up smoking.

Follow a heart-healthy eating pattern#

A heart-healthy eating pattern is important for managing blood pressure and reducing the risk of heart disease. Aim to:

• eat plenty of vegetables, fruit and wholegrains
• include a variety of healthy protein-rich foods, especially fish and seafood, legumes (such as beans and lentils), nuts and seeds – eggs and poultry can also be included
• choose unflavoured milk, yoghurt and cheese; if you have heart disease or high cholesterol, choose reduced-fat varieties
• include healthy fats and oils, such as nuts, seeds, avocados, olives and their oils for cooking
• add herbs and spices to flavor foods, instead of adding salt

This way of eating is naturally low in unhealthy fats, salt and added sugar, and is rich in wholegrains, fiber, antioxidants and healthy fats. For individualized nutrition advice, you can also speak to an accredited dietitian.

Reduce your salt (sodium)#

It’s the sodium in salt that is bad for your health, and reducing the amount you eat can help manage your blood pressure. When looking at food labels, it is the sodium that is listed. A commonly recommended daily maximum is about five grams of salt (about a teaspoon).

In addition to following a heart-healthy eating pattern, these tips can help reduce your salt intake:

• Get into the habit of checking food labels. Many packaged and processed foods (such as pizzas, pastries, biscuits and takeaway foods) are high in salt that you can’t see, so you don’t know how much you are having.
• Choose low-salt food (less than 120mg sodium per 100g) where possible, and look for labels with ‘low salt’, ‘salt reduced’ or ‘no added salt’.
• Avoid adding salt during cooking or at the table. Flavor meals with herbs and spices instead.
• Cook at home when you can. Takeaway food and food prepared outside the home is often high in salt, and preparing your own meals helps you stay in control of how much is added.

Be physically active#

Being physically active is a great way to manage your blood pressure and reduce your risk of heart disease. All types of physical activity count – walking, cycling, swimming and yoga are all great for your health. It’s important to do activities you enjoy, as you are more likely to keep active if you are having fun. It is recommended that you:

• do 30 minutes or more of moderate-intensity physical activity on five or more days per week (you can break this up into smaller bouts, such as three 10-minute walks)
• include muscle-strengthening activities on at least two days each week

Walking is a great activity for heart health and managing blood pressure, and walking with others can be a fun and social way to stay active.

Limit your alcohol#

Alcohol isn’t a necessary or recommended part of a heart-healthy eating pattern. Drinking alcohol can increase blood pressure and the risk of heart disease. If you don’t drink alcohol, don’t start.

If you do drink, a commonly recommended limit for healthy adults is no more than 10 standard drinks per week and no more than four standard drinks on any one day. Children and young people under 18 years of age should not drink alcohol. To reduce the risk of harm to their unborn child, women who are pregnant or planning a pregnancy should not drink alcohol. For women who are breastfeeding, not drinking alcohol is safest for their baby.

For people with heart disease and related conditions or risk factors, the evidence is not strong enough to recommend a safe amount of alcohol for heart health, and for some people the safest option is not to drink at all. Speak to your doctor for advice and support to cut down on alcohol.

Achieve and maintain a healthy weight#

Reaching and staying within a healthy weight range supports healthy blood pressure and reduces your overall risk of heart disease. A heart-healthy eating pattern and regular physical activity both help.

Medicines for high blood pressure#

Medicines are available to lower and manage high blood pressure. Your doctor may call them ‘antihypertensives’ (‘anti’ meaning against, and ‘hypertensive’ meaning high blood pressure). They work in different ways – some help maintain a healthy blood pressure and improve the flow of oxygen-rich blood around the body, and some help the heart to pump more easily.

Medicines for high blood pressure can include:

• thiazide diuretics
• ACE inhibitors
• angiotensin receptor blockers
• beta blockers
• calcium channel blockers

Two or more different medicines are often needed to manage blood pressure. If your doctor recommends them, it’s still important to make healthy choices with your diet and physical activity. If you need to take medicines, your doctor will advise you on the correct type and dose.

Once you start taking medicines to manage your blood pressure, you may need to take them for the rest of your life, although the dose may change over time.

Make sure you take your medicines regularly. Some things that may help you remember include:

• building them into your daily routine by taking them at the same time each day
• keeping them somewhere that will remind you, such as next to your alarm or with your morning drink
• marking the time on your calendar, or setting a daily alarm or app reminder on your phone
• asking a family member or friend to remind you
• always carrying a list of your medicines with you, including their doses and when to take them

Take any blood pressure medicine exactly as prescribed. Don’t stop or change your medicine unless your doctor advises you to.

Key points#

• High blood pressure usually does not have any symptoms, so regular checks are important.
• Blood pressure is recorded as systolic over diastolic in mmHg; the numbers above are a guide only.
• Your overall risk depends on both modifiable risk factors (which you can change) and non-modifiable ones (which you can’t).
• Lifestyle changes – not smoking, healthy eating, less salt and alcohol, activity and a healthy weight – all help manage blood pressure.
• Many people also need medicines; take them as prescribed and keep making healthy choices.

Where to get help and trusted information#

For evidence-based global health guidance, see Source: World Health Organization (WHO).