Blood Pressure UK book

Frequently asked questions


Find answers to the most common questions about living with high blood pressure.


Choose from the topics below:



Alternative treatments

What herbal medicines can I take to lower blood pressure?

People often like to look into herbal remedies such as hawthorn, hibiscus and ginkgo biloba to lower their blood pressure. There has only been a small amount of research done into these remedies and it’s not enough to know whether they work, so they shouldn’t be used as a replacement for the treatments prescribed by your doctor which have a lot of research behind them.

While herbal remedies are thought of as natural’ that does not guarantee that they are safe. If you do decide to take them as a supplement to your prescription medications, let your doctor and your herbalist know, and tell them about any other medicines you take. Some alternative medicines and herbs can interact with other medicines and be harmful.

Eating healthily and being active are both natural ways to lower your blood pressure which can make a big difference, alongside medications if you need them.

Does RESPeRATE work?

RESPeRATE is a small battery-powered device that uses musical sounds to help you slow down your breathing to lower your blood pressure. There is some evidence showing it can reduce blood pressure in the short term but how well it works in the long term is less well known.

RESPeRATE is considered a supplementary therapy by the NHS, which means your GP may be able to prescribe it for the price of a normal prescription. Because it is a supplementary therapy, it should be used alongside any other prescribed treatments but not as a replacement.

Do relaxation techniques, meditation and yoga lower blood pressure?

Although limited, there is some evidence that yoga and meditation could help to lower blood pressure. Yoga is a gentle form of exercise which can help keep you physically fit, helping to control your weight. A healthy weight can help lower your blood pressure and risk of heart disease.

The effects of meditation and yoga appear to be small and it’s not clear what effect they have in the long term, but they are safe could help with your overall wellbeing, along with other relaxation techniques such as mindfulness. For example, helping with stress and depression. These techniques can be used alongside medications and lifestyle changes prescribed by your doctor, but shouldn’t be used as a replacement for them.


Blood pressure numbers

Shouldn’t your blood pressure be 100 plus your age?

This is an old saying from a time when doctors didn’t know as much about high blood pressure. It is not true. An ideal blood pressure is 120/80mmHg or lower, and high blood pressure is 140/90 mmHg or higher, whatever your age.

The lower your blood pressure, the lower your risk of heart attack, heart failure, stroke, kidney disease and vascular dementia will be.

Learn more about what your blood pressure numbers should be with our blood pressure chart.

What is a dangerously high blood pressure?

As high blood pressure usually has no symptoms, people often don’t know they have it so they never get treatment. Over a number of years, the raised blood pressure can damage the blood vessels, leading to a heart attack, stroke, heart failure or kidney disease.

An ideal blood pressure is 120/80mmHg or lower, and high blood pressure is usually diagnosed at 140/90mmHg. In reality, the higher your blood pressure, the higher your risk of illness later on.

If your reading is over 160/100mmHg you should see your GP. If it’s over 180/110mmHg make sure you see them within 48 hours. If you have any unusual symptoms as well such as blurred vision or headaches then see them straight away.

Occasionally, blood pressure can reach very high levels, above 240/120mmHg for example. This needs to be treated immediately in A&E.

Our blood pressure chart shows how your blood pressure numbers relate to your risk of illness.

What is the ideal blood pressure reading?

An ideal blood pressure is 120/80mmHg or lower. In general, the lower your blood pressure the lower your risk of heart disease, stroke and many other illnesses in the future. See how you can look after your blood pressure and see where your numbers are on our blood pressure chart. 

Which is most important, the top or bottom number?

The top number of your blood pressure reading is your systolic blood pressure. This is the highest level your blood pressure reaches as your heart pumps blood around your body. The bottom number is your diastolic blood pressure, it’s the lowest level your blood pressure reaches between beats. The top number is more important because it gives a better idea of your risk of having a stroke or heart attack.

Having a raised systolic blood pressure but normal or low diastolic blood pressure is called Isolated Systolic Hypertension (ISH). Even though only the top number is raised, it still carries a higher risk of developing heart attacks or strokes and should be treated.

There are some circumstances where diastolic blood pressure may be more important than systolic. Some studies suggest that in people aged under 40, diastolic blood pressure gives a better idea of the risk of health problems, but as heart attacks and strokes are less common in younger people, there is less information available about blood pressure numbers and the risk of these problems.

It could be that diastolic blood pressure becomes more important when it is very high. There is some evidence to suggest that a blood pressure of 180/120mmHg gives a greater risk of stroke or heart attack than 180/100mmHg.

Find out more about what the numbers mean.

Only my top number is high - what does this mean?

This is called isolated systolic hypertension (ISH). It’s more common as people get older. It needs to be treated even though it’s only the systolic number (the top number) that’s raised, as it can still lead to health problems.

High blood pressure is usually diagnosed at 140/90mmHg and a healthy reading would be 120/80mmHg. 160/80mmHg for example is isolated systolic hypertension because only the top number is raised. It’s more likely to lead to health problems than a blood pressure of more than 150/90mmHg.

See how the numbers relate to the risk of health problems.

As you get older, do you still need to get below 140/90mmHg?

The short answer is yes. Blood pressure does tend to rise with age, but the levels to aim for with treatment are the same for all ages.

If you have diabetes, kidney disease or have already had a heart attack or stroke, your doctor may want to bring your blood pressure down lower.

Some people can find it difficult to get their blood pressure down to 140/90mmHg or lower, especially if their blood pressure was very high to begin with. But with the right treatment and lifestyle changes, most people should be able to get down to these levels.

I have diabetes, why do I have a lower target level?

If you have diabetes this raises your risk of heart disease and stroke. High blood pressure can lead to these health problems as well, and having diabetes and high blood pressure at the same time dramatically raises the risk.One important study found that if you have diabetes, keeping your blood pressure below 140/80mmHg lowers your risk of heart disease and stroke by up to a third (30%). This is why your doctor will want to keep your blood pressure below the usual target.

Diet and food

Is potassium helpful? Should I take a supplement?

Eating a range of foods that are high in potassium, especially fruit and vegetables, helps to lower your blood pressure.

Potassium plays a role in how much fluid is stored in the body and how much is released in your urine. It can lower blood pressure in part by counteracting the effects of sodium, the part of salt that puts up blood pressure by making the body hold onto water.

As long as you’re eating a healthy diet, there is no need to take potassium supplements, and they are not recommended unless they have been prescribed by a doctor. Too much potassium can be harmful, especially if you have kidney problems or you are taking certain medicines that raise the amount of potassium in your body.

If you have kidney problems you might also need to avoid potassium-based salt substitutes – known as low salts, less sodium salts, and reduced salts – as these contain high levels of potassium instead of sodium. Your doctor will be able to tell you if these are suitable for you.

Read more about potassium and your blood pressure.

Why is obesity linked to blood pressure?

Being overweight raises your blood pressure because it affects the ways your body controls blood pressure.

Your blood pressure is controlled by a number of systems, including how hard and fast your heart beats, the release of different hormones, and how much fluid your kidneys remove from your body.

Carrying too much fat appears to affect some of the hormones involved, known as the renin-angiotensin system. It interferes with the kidneys’ abilities to remove fluid and it makes your heart work harder to pump blood. All these effects can raise your blood pressure.

The good news is that losing weight will help, even losing 5-10% of your body weight can make a difference. See the simple changes you can make to lose weight.

Does eating oily fish help with high blood pressure?

Oily fish, for example sardines, trout, salmon and mackerel, are rich in a type of fat called omega 3 fatty acids. Some studies have shown that taking fish oil supplements lead to a small reduction in blood pressure. The evidence is limited and the effects are small, so fish oil supplements shouldn’t be used instead of the treatments your doctor prescribes. Ideally, you should also aim to get your nutrients from whole foods rather than supplements as they contain far more nutrients such as vitamin D and calcium.

Eating oily fish can help to balance the different types of cholesterol in your blood, helping to lower your risk of a heart attack or stroke. Find out more about fats and your blood pressure.

Try to eat fish at least twice a week, including one portion of oily fish. Because oily fish can contain low levels of pollutants, particularly mercury, there are recommendations for maximum amounts of oily fish to eat. For most people it’s four portions a week, and less for children, pregnant women and women who are trying to get pregnant.

I use a bread maker, but it says I need to use salt – should I?

Salt is totally unnecessary for making bread. Its main use in bread is to slow down the fermentation of the yeast so, without it, the bread rises quicker. Once you are used to the taste, it is fantastic – the only problem is you will want to eat too much of it.

What are the best foods to lower blood pressure?
Eating lots of fruit, vegetables and wholegrain foods will help to lower your blood pressure. Cutting back on other things will also help, especially salt and salty foods and alcohol. You should also cut back on high fat and high sugar foods.


When you’ve just been diagnosed

I'm fit and healthy, so why do I have high blood pressure?

For many people, there is no single specific cause of their high blood pressure. Your genes can play a role: you’re more likely to develop high blood pressure if you’re from an African-Caribbean or South-Asian background or people in your family have had high blood pressure.

You can lower your risk of high blood pressure by leading a healthy lifestyle.

If you have high blood pressure, medicines and a healthy lifteyle will help to lower it. 

Read more about the causes of high blood pressure.

Can high blood pressure be cured?

Lifestyle changes such as eating less salt and more fruit and veg, exercising more, losing weight and stopping smoking might be all you need to lower your blood pressure to a healthy level. Sometimes tablets are needed and these are usually very effective.

By lowering your blood pressure, with lifestyle changes or medication, your risk of having a stroke or heart attack will be much lower.

Occasionally, high blood pressure is caused by an underlying health problem, and treating the cause can bring the raised blood pressure back down to normal. There is usually an underlying cause if the blood pressure is very high, resistant to treatment, or if you have kidney disease.

See how you can lower your blood pressure.

Can high blood pressure kill me?
High blood pressure is the third biggest cause of disease in the UK. It can lead to stroke, dementia, heart attacks and heart failure, all of which can be life-threatening and cause disability. That’s why it’s so important for everyone to know their blood pressure numbers and takes steps to prevent high blood pressure or bring it down to a healthy level. 
What tests will I have done if I have high blood pressure?

As well as having your blood pressure measured several times to make sure your raised reading wasn’t a one-off, you might also have some simple tests done.

Your doctor might ask you to either measure your own blood pressure at home, or wear a small device to monitor your blood pressure over 24-hours.

Your doctor will ask you about any health problems you have or have had in the past, and illnesses in your family. You might have:

These tests help your doctor to:

  • see what your blood pressure is like outside of clinic, over a longer time period
  • see if your high blood pressure caused any damage in your body
  • find out if there is an underlying cause for your high blood pressure
  • get a better idea of your overall health and if there’s anything that could mean certain treatments aren’t suitable.

You may need more detailed investigations, your doctor will discuss these with you. Find out more about the tests that can be used if you have high blood pressure.

Do I need to get my cholesterol checked too?

High blood pressure can lead to heart disease and stroke. A raised blood cholesterol level can also lead to heart disease and stroke. If you have both at the same time, the risks are higher.

If you are diagnosed with high blood pressure you might also have a blood test to measure your cholesterol levels, particularly if you are overweight, you’re not physically active or you smoke, as these can also raise your risk of health problems.

Can I get a specialist opinion?

If you have high blood pressure you may be referred to a specialist. There are a number of reasons why you might need to see a specialist:

  • If you need to be treated very quickly, for example, if your blood pressure is very high.
  • If your doctor thinks there might be an underlying illness causing the high blood pressure.
  • If you have problems getting or keeping your blood pressure under control, for example, if your medications are causing bad side effects.
  • If your blood pressure varies a lot.
  • If you’re pregnant.

Your GP can refer you to a specialist through the NHS, or you can be seen privately.

Can high blood pressure give you headaches?

It is unusual to have symptoms from high blood pressure, most people have no symptoms which is why the only way to know if you have high blood pressure is to get a blood pressure check.

Some people do say that they can tell when their blood pressure is raised. If you have very high blood pressure, you may have some symptoms, and headaches can be one of them, along with blood shot eyes, or feeling sick or generally unwell. Visit your GP if you have any symptoms you’re worried about.

Home monitoring

What time should I take my blood pressure?

When you first start using a home monitor, measure your blood pressure in the morning and evening every day for a week.  This will give you a representative picture of your blood pressure during your normal daily life, as blood pressure can vary throughout the day.

Because there is some evidence that we are more likely to have a stroke or heart attack in the morning when we first wake up, this is a good time to take readings.

After the first week, take readings at the same time each day, for example, first thing in the morning or last thing at night. This will mean you’re comparing like with like and will make it easier to spot any changes.

There are other ways to make sure you’re getting an accurate measurement. For example, taking two to three measurements and discarding the first, which can often be higher than the others, and making sure your cuff fits and is in the right place. See our tips for measuring your blood pressure at home.

Is a wrist monitor OK to use?

An upper arm monitor will give you a more accurate reading. All of the studies on blood pressure have been done with measurements from the upper arm rather than the wrist. Wrist monitors involve an extra step because they use a special chip to adjust the reading, as blood pressure is different at the wrist compared to the upper arm.

If you still want to use a wrist monitor, follow the instructions carefully as the cuff around the wrist needs to be placed exactly at the level of the heart to give an accurate reading - you will need to rest your arm on a surface for this.

What is a normal heart rate?

Your heart rate rises and falls depending on what you're doing at the time, or have just been doing. Your heart rate is usually lower after you have been resting and while you’re asleep. It will be higher if you have just been active or you have just had a drink of tea, coffee or cola, as these contain caffeine.

A normal resting heart rate, when you are sitting still, is somewhere between 60-90bpm (beats per minute). It can be 50-60bpm in healthy people who exercise regularly.

Some blood pressure medicines will lower your heart rate and your doctor will consider this when prescribing medicines for you. Others raise them to start with. As your blood pressure goes down, your heart rate goes up in an attempt to bring your blood pressure back to where it was. This is quite normal and is due to the natural ways your body controls your blood pressure.

So, when you start a new medicine your heart may beat faster for several days or weeks, after this your body will adjust and your heart rate will return to normal.

What is Ambulatory Blood Pressure Monitoring (ABPM)?

If your GP or nurse thinks you have high blood pressure you may be offered 24-hour home ambulatory blood pressure monitoring. This is where you’re given a small monitor to wear around your waist for 24 hours. It will measure and record your blood pressure at regular intervals while you go about your normal routine.

The readings give a clear picture of your blood pressure throughout the day and night and confirm whether you have high blood pressure.

An alternative to ABPM is home blood pressure monitoring, where you use a home blood pressure monitor to take your measurements at certain points of the day.


Can I fly if I have high blood pressure?

It is generally safe for you to fly if you have high blood pressure which is well controlled. If your blood pressure is unstable or very high, talk to your doctor before you make any travel plans.

It makes good sense to see your doctor before you travel and have your blood pressure checked even if it is well-controlled. You could take your home monitor away with you too.

Read more about travelling with high blood pressure.

Can having sex be dangerous if you have high blood pressure?
Sex does raise your blood pressure, but only temporarily and only by a small amount. There are very few reports of people having a stroke or a heart attack during sex, but this is rare - your blood pressure doesn’t rise very much during sex.

Read more about sex and family planning when you have high blood pressure.
Does drinking too much coffee raise your blood pressure?
Drinking coffee only has a small effect on blood pressure so cutting down or stopping will not lower it.  Other parts of your diet, such as the amount of salt or fruit and vegetables you eat are much more important – see the changes you can make to lower your blood pressure
Can I take nasal decongestants if I have high blood pressure?

Nasal decongestants can cause a rise in blood pressure when taken in high doses, but this shouldn’t happen with normal doses. Using them excessively can cause problems, especially with the sprays, so see the packet for the doses recommended by the manufacturer.

You could measure your blood pressure once or twice after taking one of your nasal decongestant treatments. If your blood pressure is okay then it’s fine to keep on using the decongestants while you have a cold, then stop once it's cleared up.

If you have nasal problems even when you don’t have a cold, it is worth seeing your GP to have it checked out. They can refer you to an ear, nose and throat specialist if needed to find the cause of the problem.

Does stress cause high blood pressure?

The answer lies in the difference between the short-term effects of stress and the long-term effects.

Being stressed causes your blood pressure to rise temporarily. When you feel stressed, your body releases the hormone adrenaline, raising your heart rate and your blood pressure to get your body ready for action. This is known as the flight or fight response. This only lasts a few minutes and then your blood pressure will return to normal.

True high blood pressure is where your blood pressure is raised for weeks, months or years. There is no evidence that short bursts of adrenaline and the brief rise in blood pressure they cause have any lasting effect on the body.

Stress does not appear to directly cause long-term high blood pressure, but feeling stressed over a long time can take its toll on your health.

Sometimes people deal with stress in ways that can lead to high blood pressure and heart disease, for example smoking, drinking alcohol or eating ‘junk food’ that is high in salt, as well as struggling to find time to exercise.

Find out more about stress and high blood pressure.

Why is cold weather bad for people with high blood pressure?

It is true that more people have heart attacks or strokes in the winter than in the summer. Cold temperatures make your blood vessels constrict, which helps to conserve heat and maintain body temperature. It also means that there is less room for your blood to flow through, raising your blood pressure and heart rate, and thickening the blood as well.

If you already have narrowed arteries due to atherosclerosis, where fat builds up in the artery walls, these changes can cause chest pains (angina) and raise the chances of blood clots forming in the arteries, leading to a heart attack or stroke. The risk of these happening is higher if you have high blood pressure.

Learn about ways to lower your blood pressure


Medicines for high blood pressure

Why are different people given different medicines?

People respond differently to blood pressure medicines. A number of things can affect how you respond to each medicine, including your ethnic background, age and how much salt you eat. It can take some trial and error to find the medicine or combination of medicines that works best for you.

Younger, non-black people (not of African or Caribbean origin) tend to respond slightly better to ACE inhibitors and angiotensin receptor blockers. Older people and those of African or Caribbean origin tend to respond better to calcium-channel blockers and thiazide diuretics.

These will usually be the first medicines you’re offered, aiming to keep the number of medicines needed to a minimum. Read more about finding the right medicines for you.

Why does eating less salt help medicines to work?

Eating less salt can help ACE inhibitors and angiotensin receptor blocker (ARBs) to work better. These medicines block a hormonal system called the renin-angiotensin system which is important in blood pressure control, and blocking it helps to lower blood pressure.

The renin-angiotensin system tends to be more important in younger people and those with lower salt intake, and eating less salt helps these medicines to work better.

If you are older or from African or Caribbean backgrounds you wouldn’t normally be given ACE inhibitors and angiotensin receptor blocker (ARBs) as a first choice, but lowering your salt intake could mean they work just as well as the drugs which are normally used – calcium-channel blockers or thiazide diuretics.

Can I ever come off tablets once I start taking them?

For most people, the answer to this is no. Once you find out you have high blood pressure and need tablets, it is likely that you will have to take the tablets for the rest of your life. If you make lifestyle changes such as exercising more and eating less salt and your blood pressure is under control for several years, it’s possible that you might be able to stop taking them or take a lower dose.

Sometimes people stop taking their medicines once their blood pressure is under control thinking they don’t need them anymore. It’s important that you don’t simply stop taking your medicines because your blood pressure will go back up within a few weeks.

High blood pressure is something that affects your health in the long-term, so it’s important to keep it controlled in the long-term.

Should I be taking aspirin as well?

If you have high blood pressure, your doctor might recommend that you take aspirin if you are at a higher risk of heart attacks or strokes, for example, if you have had an ischaemic stroke caused by a blood clot or heart attack in the past. This is because aspirin thins your blood and prevents blood clots from forming.

Do not start taking aspirin regularly unless your doctor advsises you to because aspirin's ability to prevent clots can raise the risk of bleeding from the stomach and intestines, it might also be linked to a higher risk of strokes caused by burst blood vessels.

Does it matter what time of day I take my medicines?

It's best to take your medication at the same time every day so that it becomes part of your routine and could help you remember to take them. It doesn’t really matter whether you take them in the morning or the evening, it’s whatever suits you best.

Diuretics, sometimes called water tablets, can make you need to urinate (pee) more often, especially to begin with, so you might prefer to take them in the morning so you don’t have to keep getting up in the night.

My medication isn’t working – what can I do?

If you are taking just one tablet and it isn’t working well or is causing you side effects, your GP may switch you to another tablet. If it is working and isn’t causing problems, but your blood pressure is not at the target level, then your GP might add a second medicine. The tablets should work better together than they do separately.

It’s normal to take two or three different tablets together to get good control of blood pressure. If your blood pressure is still not well controlled, your doctor may add in other medications or try different groups of medications. It can take some trial and error.

Once your blood pressure is under control, you should be able to stay on the same tablet or combination of tablets for a long time without needing to change them. Remember that changes in lifestyle, particularly eating less salt, make the tablets more effective.

Should I spread out taking my pills across the day?

Most blood pressure lowering drugs are long-acting, meaning you can take them just once a day. If you are taking more than one type, there is no evidence that it helps to take them at different times, so take them at the time or times that suits you best.

The most important thing is to take each tablet at the same time every day so that their effect covers the full 24 hours. Taking them at the same time each day can also help you remember to take them.

Some people find it more convenient to take their tablets in the evening when they get home from work. Others prefer to take them first thing in the morning. The most important thing is to stick to a routine and take your tablets every day.


Physical activity and sports

How much activity is needed to lower my blood pressure?

To lower your blood pressure, aim to do at least 30 minutes of moderate activity five times a week. Moderate activity is activity that gets you slightly warm and out of breath, but you should still be able to have a conversation – brisk walking, swimming, cycling and gardening for example.

If you are starting from scratch, or you have other medical conditions, you may need to build up to this level gradually. You can break your session up into 15 minutes twice a day or ten minutes three times a day.

Are there any sports or activities I should avoid?

Choose activities which allow you to work at a level that’s light to moderate, but not hard or very hard. Think about how the activity feels – you should feel slightly warm but not hot, you should breathe a little harder without getting out of breath, and your muscles should be working but you shouldn’t feel exhausted. If you can’t hold a conversation whilst you are exercising, then you are working too hard.

There are certain activities you should avoid because they can raise your blood pressure to dangerous levels while you’re exercising:

  • lifting heavy weights without supervision from a qualified exercise trainer
  • vigorous short bursts of exercise, for example boxing, squash, spinning (exercise classes on a stationary bike) or High Intensity Interval Training (HIIT).

Depending on your blood pressure, it might not be safe for you to scuba dive. Let your diving instructor know you have high blood pressure, and you will need to be passed to dive by a diving medical specialist.

Other sports and activities, which can involve high speeds and changes in atmospheric pressure may also require a medical certificate, for example parachuting and motor racing.

If you are in any doubt, contact the governing body for the activity you want to try.

Why shouldn’t I lift weights?

There are two main types of physical activity – aerobic (or dynamic) and isometric (or static) exercise, and our bodies react differently to them. Ideally, we should do some of each type, but if you have high blood pressure, some types of exercises won’t be suitable. 

Aerobic (dynamic) exercise
Aerobic exercises get the heart and lungs working. They use the large muscle groups in your body, often in repeated and rhythmic movements. They’re sometimes called dynamic exercises because you move through a whole range of movement. They include swimming, cycling, brisk walking, tennis, dancing and heavy gardening.

Aerobic exercise is very good for your heart and blood vessels as it gives them a good workout, helping them to become more flexible and keeping them in good shape.

During aerobic exercise, your heart pumps your blood with more force which does raise your blood pressure a little, but because the blood flows into a large number of muscles around the body, the blood has plenty of space to flow through and your blood pressure won’t rise very much. In fact, regular aerobic activities will help to lower your blood pressure over time. Just avoid pushing yourself too hard.

Isometric (or static) exercises are exercises which build muscle and strength, for example weight lifting and using resistance bands. They’re sometimes called static exercises because you will stay in one place, for example with bench press where you lay flat and push against a bar.

Some types of isometric exercise, including lifting heavy weights, can raise your blood pressure very high very quickly while you’re doing the exercise. This puts extra strain on the heart and blood vessels, so they might not be suitable for you if you have high blood pressure. Light weights wont be a problem. 

Isometric exercises involve the sustained contraction of just one set of muscles, rather than the whole body. The heart beats with more force, but only a small number of muscles are being used meaning there is less space in the for the blood to flow in, causing the rise in blood pressure.

Speak to your doctor or a qualified fitness professional before taking on a new exercise to make sure it’s safe for you. Read more about physical activity and your blood pressure.


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