29 December 2005

Blood Pressure - a useful guide to understand and control your blood pressure.

Blood Pressure

Blood pressure is the pressure of blood in your arteries. The higher your blood pressure the greater your risk of developing narrowed arteries, which can lead to heart problems and strokes. The good news is that if your blood pressure is high, it can be lowered by making changes to your lifestyle, for example changing your diet, exercising and losing weight, and when needed, with tablets. This will reduce your risk of developing heart and brain problems that might otherwise occur if your blood pressure is not treated. However, in many people, blood pressure is not checked or measured and in some people who have high blood pressure it may not treated adequately.

This information is designed to give you more information about your blood pressure. This will help you to understand more about your treatments and to help you to play a greater role in keeping your blood pressure controlled.

What is blood pressure?

Your heart pumps blood around your body through a network of tubing called arteries. Every time your heart pumps it forces blood through these arteries and into smaller blood vessels called capillaries. The force that your heart produces in your arteries when it pumps is called your blood pressure. When the heart contracts and forces blood through the arteries your blood pressure goes up, when the heart relaxes it goes down.

This pressure can be measured and is usually written down like this:


The top number, which is called the systolic pressure, shows the pressure in your arteries when your heart is forcing blood through them. The bottom number, called the diastolic pressure, shows the pressure in your arteries when your heart relaxes. The top number can be anywhere from 90 to 240 and the bottom number can be anywhere from 60 to 140. Blood pressure is measured in millimetres of mercury, which is written down as: mmHg

Everyone has a different blood pressure and it can change in the same person during the day and night.

What is high blood pressure?

High blood pressure can also be called hypertension; both words mean the same thing. The higher your blood pressure, what ever it is, the higher your risk of heart disease or stroke.

140/90mmHg is the level of blood pressure used to diagnose high blood pressure. If your blood pressure is consistently raised at these levels and above, it will need to be treated. Treatment may involve making changes to your lifestyle and/or taking medication. This level of 140/90mmHg is the level for high blood pressure for everyone, whether you are male or female, young or old.

High blood pressure can be a systolic reading of 140 or above, a diastolic reading of 90 or above, or both. For example, a reading of 150/85mmHg is high because the systolic is above 140; a reading of 139/95mmHg is high because the diastolic is above 90. A reading of 150/95mmHg is also high as both the systolic and the diastolic number are raised. As you get older you may find that your diastolic level is normal but your systolic level starts to rise and this is called isolated systolic hypertension. This is common among older people, and still needs to be treated.

140/85mmHg is the target blood pressure for people who are receiving treatment for their high blood pressure. The only exception to this target level is if you have diabetes, kidney disease or have already suffered a stroke or heart attack. Then it may be worthwhile lowering your blood pressure even further.

Why is high blood pressure important?

High blood pressure is a risk factor for heart disease, stroke, kidney disease and dementia. This means that if you have high blood pressure you are at greater risk of developing these conditions than someone who does not have high blood pressure.

Having high blood pressure causes strain on the vessels carrying blood around your body. This strain can cause vessels to become clogged up or to weaken and this in turn can lead to narrow blood vessels and clots, which can cause damage to the heart or brain. More rarely it can lead to the blood vessels bursting. Having high blood pressure can also cause heart failure. Heart failure is when your heart can not pump blood around the body as well as it should and this can cause you to become short of breath and can cause your ankles to swell. High blood pressure can cause kidney failure, some eye conditions, and there is some research that shows that by lowering blood pressure you may be able to prevent some types of dementia. So, there are many very good reasons for controlling your blood pressure both and now and in the future.

High blood pressure is a serious condition, and one that you should not ignore. However, the really good news is that it can be lowered either by changing your lifestyle or if necessary adding in tablets. The lower you can get your blood pressure the lower your risk of heart disease, stroke, kidney disease and dementia.

How common is high blood pressure?

In the United Kingdom there are about 16 million people with a blood pressure higher than 140/90mmHg. One in every three women and two in every five men now have high blood pressure, with larger numbers affected in older age groups. For example, about half of all people over the age of 75 have the condition. Although you may be said to have high blood pressure, or a normal blood pressure, it is important to realise that the higher your blood pressure, whatever it is, the higher your risk of heart disease or stroke. This means that all of us should be adopting a lifestyle that will help to lower our blood pressure whether we have high blood pressure or not.

How is blood pressure measured?

Your blood pressure can be measured either by using a device called a sphygmomanometer or by using a digital machine.

A sphygmomanometer is the older kind of equipment that measures blood pressure using a column of mercury. The person taking your blood pressure will put a cuff around the top of your arm, pump up this cuff and then listen for sounds through a stethoscope placed on your arm. The sounds heard through the stethoscope will start, and then finish, at certain points on the mercury column, and this will give the reading for your blood pressure. There are also automatic, or partly automatic, digital machines that can measure blood pressure. They also use a cuff around your arm and will give a readout of your blood pressure.

In order to be sure that you have high blood pressure, you will be asked to have readings taken several times. This is to make sure that you have consistently high blood pressure, rather than high blood pressure because you are nervous at the doctors or have rushed to get to your appointment.

What causes high blood pressure?

A small number of people have what is called secondary hypertension, which means that there is an underlying cause of their high blood pressure. For example, some people develop high blood pressure if they have problems with their kidneys or the adrenal glands, which sit above the kidneys. These glands produce hormones that are important in controlling blood pressure.

However, for most people there is no definite cause for their high blood pressure and doctors call this essential hypertension. The small blood vessels in the body narrow and this causes the pressure to build up, a bit like squeezing a garden hose.

High blood pressure can run in the family, and if you have a parent with high blood pressure then you are more likely to have high blood pressure yourself.

If you are black then you are more likely to have high blood pressure than the rest of the population in the United Kingdom; you may be more sensitive to salt in your diet and more likely to have a stroke. If you are South Asian then you are more likely to have diabetes or a heart attack which means that it is important for you to keep your blood pressure and cholesterol well controlled. The reasons for this are not fully understood.

Some other conditions are also linked to high blood pressure, such as diabetes, kidney disease and heart disease. If you have any of these conditions then it is even more important that your blood pressure is well controlled.

Your blood pressure is very much affected by your lifestyle. The important factors are:

· Eating too much salt
· Not eating enough fruit and vegetables
· Not exercising enough
· Being overweight
· Drinking excessive amounts of alcohol

Whereas you cannot change your genes, or the fact that you will grow older, you can change your lifestyle. Changing your diet and exercising more will lower your blood pressure. This is something that everyone should do but is particularly important if you have high blood pressure as it may avoid the need for tablets.

Can high blood pressure be treated?

High blood pressure is not usually something that you can cure, but it can be treated. Lowering blood pressure causes a large reduction in strokes, heart attacks, heart failure and kidney disease that would otherwise have occurred and may reduce your risk of developing some kinds of dementia.

How will my high blood pressure be treated?

How your high blood pressure is treated will depend on how high it is and on what other ‘risk factors’ you have for heart disease and stroke.

If your blood pressure is between 140-160/90-100mmHg then you will probably be asked to make some changes to your lifestyle. You will probably not need to take tablets providing that the changes you make work. In this way you can lower your own blood pressure without needing to take tablets. However, some people with a blood pressure in this range may be prescribed medication to take. This is usually if they are older or have other risk factors for heart disease and stroke, such as high cholesterol, smoking or already have complications such as a previous stroke or heart attack.
So if you have a blood pressure reading in this range you should:

· Cut down the amount of salt you are eating
· Eat at least seven to nine portions of fruit and vegetables every day
· Take more exercise
· Lose weight if you are over weight
· Cut down on the amount of alcohol you are drinking, if it is excessive

If your blood pressure is consistently over 160/100mmHg then you will probably be given tablets to take as well as being asked to make changes to your lifestyle. You are aiming to reach a target blood pressure of 140/85mmHg or less whilst making sure that you feel fit and well. There will, however, be a small number of people who may find their blood pressure very difficult to control even with medication.

Changing your lifestyle.

All people who have high blood pressure should make changes to their lifestyle. These changes can be enough to lower your blood pressure to a level where you may not need to take tablets. Even if you need tablets, the changes to your lifestyle will make the tablets more effective.

These changes to your lifestyle should be adopted by the whole family, as, increasing evidence suggests that this will lower blood pressure and prevent high blood pressure from occurring later in life. A healthy diet will also make you feel much better.

These are the five main changes you can make:

1. Cut down on your salt

We each eat about 10 grams of salt (sodium chloride) each day and this can easily be reduced by half to 5 grams each day. That means cutting down from a dessert spoon of salt every day to a teaspoon. You should not add salt to food or use it in cooking. However, most salt is hidden in many processed foods and this may not be obvious, for example salt may be hidden in bread, many cereals and ready meals so avoid these high salt foods where possible.

2. Eat more fruit and vegetables

We should all be eating seven to nine portions of fruit or vegetables each day. Fruit and vegetables contain potassium, which has the opposite effect of salt and can help to lower blood pressure. If you can manage to increase the amount of fruit and vegetables and cut down the amount of salt that you eat then you should see your blood pressure fall by quite a large amount.

3. Be more active

Being active can help you to lower your blood pressure. It will also help you to lose weight and reduce the amount of fats (cholesterol) in your blood. If you are not very active now then you do need to take care to begin with and build up gradually. Being active doesn't have to mean jogging, it can mean walking the dog regularly and gradually increasing the amount you do over three to six months. You are aiming to be active for at least 30 minutes, five times a week.

4. Find and reach your ideal weight

Everyone has an ideal weight. Your ideal weight will depend on how tall you are and whether you are male or female. If you are overweight you should try and get down to a weight within the ideal range for you.

Many people find losing weight, and maintaining weight loss, difficult. A healthy diet is an essential first step. Once you are eating a healthy diet cut down the amount of food you eat until you start to lose weight.

5. Drink alcohol in moderate amounts only

This means that if you are a man you should be drinking no more than three to four units each day and if you are a woman you should be drinking no more than two or three units each day. If you are regularly drinking over these amounts then it is likely to affect your blood pressure and you should cut back. However, if you are sticking to moderate amounts then you do not need to cut down but you should avoid binge drinking.

As well as the five factors set out above there are two other key risk factors for stroke and heart disease, smoking and eating too much saturated fat. They don't in themselves cause high blood pressure but they do make you more at risk of heart disease or stroke. However, the combined effect of stopping smoking, cutting down the amount of saturated you eat and lowering your blood pressure causes a very large reduction in your risk of having a stroke or having a heart attack.

Giving up smoking

Smoking is the biggest risk factor for having a heart attack. If you smoke it will not directly affect your blood pressure, but it will cause your arteries to narrow, just as high blood pressure does. So, if you smoke and you have high blood pressure your arteries will narrow much more quickly. There are now lots of ways in which you can make giving up smoking easier for yourself. Nicotine replacement therapy, in the form of patches and gum, for example, and groups to help smokers quit are just a few. If you have difficulties talk to your doctor or nurse.

Cutting down on saturated fat

We all eat too much fat. The type of fat that causes the most problems is saturated fat, for example animal fats and some vegetable oils such as palm and coconut oil. Fat increases the amount of cholesterol in your blood. The higher the level of cholesterol in your blood the greater your risk of heart disease and stroke. If you have high blood pressure reducing you saturated fat intake is very beneficial.

These changes to your lifestyle will reduce your risk of heart disease or stroke, but they may not lower your blood pressure enough. It may be necessary for you to take tablets as well.

Medicines for high blood pressure

If you need tablets, there is very strong evidence that they will reduce your risk of stroke and heart disease, provided your blood pressure is well controlled. Tablets can prolong life and reduce the risk of complications from high blood pressure. In most people lowering blood pressure with tablets causes no problems, in fact many people feel better.

As with any medicines, those for high blood pressure can occasionally cause side effects in some people. Most of these side effects are rare and will only happen in a small number of people. However, it is vitally important that if you feel that any medicine that you are taking is causing you to feel unwell that you go back to your doctor and talk about it. You can change your tablets to find the ones that keep your blood pressure controlled, and leave you feeling well. Most people will need more than one tablet to control their blood pressure and it may take some time to find the combination of tablets that are right for you.

There are now several different kinds of tablets that can be used to treat high blood pressure. They all work in a different way inside the body and some kinds of tablets may suit you better than others. The aim of any tablet, combined with lifestyle changes, is to get your blood pressure to below 140/85mmHg.

Taking tablets for high blood pressure is something that most people will have to do for the rest of their lives and continuing to take them is very important. You may have no symptoms from your high blood pressure, but if it is left untreated you will put yourself at risk from heart disease or stroke. As soon as you stop taking tablets your blood pressure will go back up, as will your risk of heart attack or stroke. Many people find that once they get into a routine with their tablets, they become a part of their daily lives, like cleaning their teeth. It is important that you remember to take them and that you remember to renew your prescription before you run out. If you are worried about any aspect of taking you tablets speak to your doctor or nurse.

The purpose of both the lifestyle changes that you make and the tablets that you take is to control your blood pressure with you feeling completely well, or feeling much better. Once your blood pressure is controlled you should be able to lead your life as you normally would. A small number of people suffer more serious or prolonged side effects from medications and may need to see someone who specialises in managing high blood pressure, who can help them to find the right tablets.

The table at the end of this leaflet explains how these medicines work, what problems may occur with them and how they can affect you. New medicines are being developed all the time, and treatment options may change.

Frequently asked Questions

Can you tell when your blood pressure is high?

Usually the only way to know if you have high blood pressure is to have it measured. Most people cannot tell if their blood pressure is high any other way. Symptoms such as a headache or dizziness are very unusual, which is why it is important for you to have you blood pressure checked regularly. This is why high blood pressure is often known as the silent killer.

Should I measure my blood pressure at home?

Many people do measure their blood pressure at home as it helps them to feel more in control of their condition. There are a number of digital machines available for home use. If you are thinking of buying a machine, buy one that measures blood pressure from the top of your arm rather than at the wrist as, at the moment, these tend to give more accurate readings.

Your blood pressure readings will be lower at home because you are usually more relaxed. Make sure that you keep a record of your readings to pass onto your doctor or nurse.

How does age affect blood pressure?

As you get older your blood pressure is likely to rise. This means that you need to have your blood pressure checked every year so that if it does start to rise you can take steps to lower it, such as changing your lifestyle. It does not matter what age you are, 140/90mmHg is the level for high blood pressure for everyone, whether you are 20 or 80. The old saying that the top number (systolic) of you blood pressure should be 100 plus your age is not true.

Will I need to have any tests or investigations?

As well as having your blood pressure measured several times it may also be necessary for you to have some simple tests done. Your doctor will usually ask about your family and medical history, will often give you a urine and blood test and may also ask you to have a recording of the electrical activity of your heart (ECG). Some people may also have blood pressure monitoring over a 24-hour period. A few people may need more detailed investigations but your doctor will discuss these with you.

How long does it take for lifestyle changes and medications to work?

This largely depends upon the individual. Reducing the amount of salt and increasing the amount of fruit and vegetables that you eat usually takes a few weeks to start having an affect on your blood pressure. Increasing the amount of exercise you do, and losing weight are more likely to take longer. Once you start taking a new medicine your doctor will usually ask you to take it for a month and then check your blood pressure after that. By this time you should see how effective they are. However, not everyone finds the right tablet for them straight away and you may need to try several until you find one that works and that you feel happy taking.

Are there any other medicines that I can't take if I am taking tablets for blood pressure?

Whenever you have other medicines, whether they are from your doctor or from your chemist always tell them that you are taking tablets for your high blood pressure. Some cold and flu medicines and some painkillers (non-steroidal anti-inflammatories like Ibuprofen and voltarol) can interfere with some tablets for high blood pressure.

Does stress cause high blood pressure?

Many people do think that stress can cause high blood pressure, particularly long term stress at work or at home. Stressful situations can cause your blood pressure to go up in the short-term, but it will come back down once that stress has gone. Long-term stress is not thought to cause high blood pressure on its own. However, if as a result of your stress you also have an unhealthy lifestyle, drinking alcohol excessively and being overweight for example, this may have an effect on your blood pressure.

If I have high blood pressure, will my children have it?

High blood pressure does run in families and it is even more important that if you have high blood pressure that you help your children to lead a healthy lifestyle too. If your children follow the same diet that you should be following, take exercise and avoid being overweight they should be able to reduce their own risk of developing high blood pressure too.

How often will I need to see my doctor?

When you first find out that you have high blood pressure you will probably need to see your doctor quite regularly, to get your blood pressure checked. Your doctor will also want to make sure that if you are taking tablets your blood pressure is well controlled and you feel well taking them. Once your blood pressure is well controlled then you will need to go less often. Your practice nurse can check your blood pressure and manage your condition and it may only be necessary for you to see your doctor every six months or every year, particularly if you check your own blood pressure at home. Everyone is different. Discuss your visits with your practice nurse and/or your doctor.

Key points

· High blood pressure is very common in the United Kingdom. Many people with high blood pressure don't know that they have it until it's too late
· High blood pressure that is not treated can lead to a heart attack, heart failure, stroke and kidney disease
· High blood pressure can rarely be cured but it can be treated very effectively
· Taking medicines and making changes to your lifestyle, such as reducing salt, eating fruit and vegetables and watching your weight can help to bring your blood pressure down and keep it down
· If you need to take tablets to treat your blood pressure will almost certainly have to take them for life. However, they should not make you feel unwell or interfere in any way with your day-to-day activitiesOnce your blood pressure is controlled you should feel and think of yourself as completely well