Last Updated: 11 December 2018
Schematic diagram showing a patient having his blood pressure manually taken.
The only way of knowing there is
a problem is to have your blood pressure measured. All adults should have their blood
pressure checked at least every five years. If you haven’t had yours measured,
or you don’t know what your blood pressure reading is, ask your doctor to check it
for you.
What is high blood pressure?
Blood pressure is measured in
millimetres of mercury (mmHg) and is recorded as two figures:
- systolic pressure – the pressure of the
blood when your heart beats to pump blood out.
- diastolic pressure – the pressure of the
blood when your heart rests in between beats, which reflects how strongly
your arteries are resisting blood flow.
For example, if your doctor says 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.
You are said to have high blood
pressure (medically known as hypertension) if readings on separate
occasions consistently show your blood pressure to be 140/90mmHg or
higher.
A blood pressure reading below 130/80mmHg
is considered to be normal.
Who is most at risk?
Your chances of having high blood
pressure increase as you get older. There is often no clear cause of high blood
pressure but you are at increased risk if you:
- are overweight
- have a relative with high blood pressure
- smoke
- are of African or Caribbean descent
- eat too much salt
- don't eat enough fruit and vegetables
- don't do enough exercise
- drink too much coffee (or other caffeine-based drinks)
- drink too much alcohol
- are aged over 65.
Prevalence of hypertension in the different states of USA.
If you fall into any of the groups
listed above, consider making changes to your lifestyle to lower your risk of high blood pressure. Also
consider having your blood pressure checked more often, ideally about once a
year.
Prevention and treatment
You can take steps to prevent high
blood pressure by:
- losing weight if you need to
- reducing the amount of salt you eat
- exercising regularly
- eating a healthy diet
- cutting back if you drink too much alcohol
- stopping smoking
- cutting down on caffeine.
If your blood pressure is found to be
high, it will need to be closely monitored until it is brought under control.
Your doctor will usually suggest changes to your lifestyle and, sometimes,
medication to achieve this.
Causes of high blood pressure
In more than 90% of cases, the cause
of high blood pressure (hypertension) is unknown but several factors can
increase your risk of developing the condition. Where there is no specific cause,
high blood pressure is referred to by doctors as primary or essential
hypertension.
Factors that can raise
your risk of developing primary hypertension include:
- age – the risk of developing high blood pressure increases as you
get older
- a family history of high blood pressure (the condition seems to run
in families)
- being of African or Caribbean origin
- a high amount of salt in your food
- a lack of exercise
- being overweight or obese
- smoking
- drinking large amounts of alcohol.
Known causes
About 10% of high blood pressure
cases are the result of an underlying condition or cause. These cases are
referred to as secondary hypertension. Common causes of secondary
hypertension include:
- kidney disease
- diabetes
- narrowing of the arteries (large blood vessels) supplying the
kidneys
- hormonal conditions, such as Cushing's syndrome
- conditions that affect the body’s tissue, such as lupus
- oral contraceptive pill
- painkillers known as nonsteroidal anti-inflammatory drugs (NSAIDs),
such as ibuprofen
- recreational drugs, such as cocaine, amphetamines and crystal
methamphetamine
- herbal remedies, such as herbal supplements.
Symptoms of high blood pressure
High blood pressure (hypertension)
usually has no obvious symptoms and many people have it without knowing. Untreated high blood pressure can
lead to serious diseases, including stroke, heart disease and kidney failure.
The only way to know if you have high
blood pressure is to have your blood pressure measured. All adults
should get their blood pressure checked at least once every five years.
In some rare cases, where a person
has very high blood pressure, they can experience symptoms, including:
- a persistent headache
- blurred or double vision
- nosebleeds
- shortness of breath.
Visit your family doctor as soon as possible, if
you find that you have any of these symptoms.
Pregnancy
If you are pregnant, it's important
to have your blood pressure checked on a regular basis, even if it isn't high. Watching your blood pressure while
you are pregnant reduces your risk of developing pregnancy-induced
hypertension.
This can lead to a serious condition
called pre-eclampsia where there is a problem
with the placenta (the organ that links the baby’s blood supply to the
mother’s).
Getting a blood pressure test
High blood pressure (hypertension)
often doesn't have any symptoms, so the only way to find out if you have it is
to get your blood pressure checked. Having this done is easy and could
save your life.
Blood pressure testing is
available in a variety of settings:
- at your doctor's surgery by a doctor, practice nurse, healthcare assistant or
self-service machine
- at a pharmacy
- as part of your Health Check
- in some workplaces
- at a health event
- at home – you can check blood pressure yourself with a home
testing kit.
Healthy adults aged over 40 should
have their blood pressure checked at least once every five years. If you are at an increased risk of high blood pressure, you
should have your blood pressure checked more often, ideally once a year.
You can ask for a blood pressure
check – you don't have to wait to be offered one. Blood pressure testing is also part
of the General Health Check for adults over the age of 40.
The test
Blood pressure can be measured using
a manual or automatic device. A cuff is placed around your arm
and pumped up to restrict the blood flow. The pressure is
then slowly released as your pulse is checked.
Hearing how your pulse beats after
the cuff is released allows a measurement to be taken, giving a blood pressure
reading. Before having your blood pressure
taken, you should rest for at least five minutes and empty your bladder.
To get an accurate blood pressure
reading you should be sitting down with your back supported and legs
uncrossed, and not talking when the reading is taken.
Confirming if you have high blood
pressure
Having a raised blood pressure
reading in one test does not necessarily mean you have high blood pressure.
Blood pressure can fluctuate throughout the day. Feeling anxious or stressed
when you visit your doctor can also raise your blood pressure.
If you have a high reading, you
will probably be given a blood pressure kit to take home, or be asked to
wear a 24-hour monitor so you can monitor your blood pressure level
throughout the day. This will confirm whether you have consistently high blood
pressure.
You may also have blood and urine
tests to check for conditions that are known to cause an increase in blood
pressure, such as kidney disease.
Schematic diagram showing the possible damage effect from high blood pressure.
Home testing
Portable machines that measure your
blood pressure at home or on the move can be a useful way of getting a more
convenient and accurate reading. This is because some people become
anxious in medical clinics, which can cause the blood pressure to rise. This is
a condition called "white coat hypertension".
Home or portable blood pressure
monitors may show that your blood pressure is in fact normal when you are
relaxed.
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.
The British Hypertension Society
(BHS) website has detailed information about clinically approved blood pressure monitors that
are available to buy.
Understanding your blood pressure
reading
Blood pressure is measured in
millimetres of mercury (mmHg) and it is recorded as two figures:
- systolic pressure (the top number) –
the pressure of the blood when your heart pushes blood out
- diastolic pressure (the bottom number) –
the pressure of the blood when your heart rests in between beats, which
reflects how strongly your arteries are resisting blood flow.
If your doctor says 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. Ideally, your blood pressure reading
should be below 120/80mmHg (for the lowest possible risk of disease). However,
anything under 130/80mmHg is generally considered normal.
You are said to have high blood
pressure if readings on separate occasions consistently show your blood
pressure to be 140/90mmHg or higher. If you have kidney disease, diabetes
or a condition that affects your heart and circulation, your target blood
pressure should be below 130/80mmHg.
Treating high blood pressure
You can take effective steps to lower
your blood pressure with changes to your lifestyle and by taking medication. In all cases, you can benefit from
making some simple lifestyle changes. Whether you are also
recommended to take medication will depend on your blood pressure level and
your risk of developing a cardiovascular disease, such as a heart attack, stroke or kidney failure.
- If your blood pressure is consistently above 140/90mmHg (or
135/85mmHg at home) but your risk of cardiovascular disease is low –
you should be able to lower your blood pressure by making some changes to
your lifestyle (see below). You may be offered yearly blood pressure
assessments.
- If your blood pressure is consistently above 140/90mmHg (or
135/85mmHg at home) but below 160/100mmHg –
you will be offered medication to lower your blood pressure if you have
existing or high risk of cardiovascular disease.
- If your blood pressure is consistently above 160/100mmHg –
you will be offered medication to lower your blood pressure.
Lifestyle changes
Below 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, others may take longer.
- Cut your salt intake to less than 6g (0.2oz) a day.
- Eat a healthy, low-fat, balanced diet,
including plenty of fresh fruit and vegetables.
- Be active: being physically active is one of the most
important things you can do to prevent or control high blood pressure.
- Cut down on alcohol.
- Lose weight.
- Stop smoking. Smoking greatly increases your chances of
getting heart and lung diseases.
- Drink less coffee, tea or other caffeine-rich drinks such as cola.
Drinking more than four cups of coffee a day may increase your blood
pressure.
You can take these steps
today, regardless of whether or not you're taking blood pressure
medication. You don’t need a doctor to prescribe lifestyle changes. The more healthy habits you adopt,
the greater effect there is likely to be on your blood pressure.
In fact, some people find that, by
sticking to a healthy lifestyle, they do not need to take any medicines at all.
Medication
There is a wide range of blood
pressure-lowering medicines to choose from and a combination
is usually needed to treat high blood pressure most effectively and with
the minimum side effects. Taking such a combination of
medication is nothing to worry about. The different types of medication work in
different ways on your body.
The first medication you are offered
will depend on your age.
- If you are under 55 years old –
you will usually be offered an ACE inhibitor or an angiotensin
receptor blocker (ARB).
- If you are aged 55 or older (or you're any age with African or
Caribbean family origin) – you will usually be
offered a calcium channel blocker.
In some cases, you may need to take
blood pressure-lowering medication for the rest of your life. However, if your
blood pressure levels stay under control for several years, your doctor might
be able to reduce or stop your treatment.
It's really important you take your
medications as directed. If you miss doses, the treatment will not work as
effectively and you could lose protection against future illness. The
medication won't necessarily make you feel any different, but this doesn't mean
it's not working.
Here are some questions you might like to ask your doctor or nurse
about your treatment. You can also ask your pharmacist any
questions about your medication, or approach them for advice on how to
stick to your treatment plan.
Medications used to treat high blood
pressure can have side effects but most people don't experience any. If they
do, the large choice of blood pressure medicines means that they can often
be resolved by changing treatments. Let your doctor or nurse know if you have
any of the following common side effects while taking medication for high blood
pressure:
- feeling drowsy
- pain around your kidney area (on the side of your lower back)
- a dry cough
- dizziness, faintness or lightheadedness
- a skin rash
- swelling of your feet.
ACE inhibitors
Angiotensin-converting enzyme (ACE)
inhibitors reduce blood pressure by relaxing your blood vessels. The most
common side effect is a persistent dry cough. If side effects become
particularly troublesome, a medication that works in a similar way to ACE
inhibitors, known as an angiotensin-2 receptor antagonist (ARB), may be
recommended.
ACE inhibitors can cause
unpredictable effects if taken with other medications, including some
over-the-counter ones. Check with your doctor or pharmacist before taking anything
in combination with this medication.
Calcium channel blockers
Calcium channel blockers keep calcium
from entering the muscle cells of the heart and blood vessels. This widens your
arteries (large blood vessels) and reduces your blood pressure.
Drinking grapefruit juice while taking some types of
calcium blockers can increase your risk of side
effects. You can discuss the possible risks with your doctor or
pharmacist.
Diuretics
Sometimes known as water pills,
diuretics work by flushing excess water and salt from the body through urine.
Beta-blockers
Beta-blockers work by making your
heart beat more slowly and with less force, thereby reducing blood pressure. Beta-blockers used to be a popular
treatment for high blood pressure, but now they only tend to be used when other
treatments have not worked. This is because beta-blockers are considered
to be less effective than the other medications used to treat high blood
pressure.
Complications of high blood
pressure
High blood pressure (hypertension)
puts extra strain on your heart and blood vessels. If untreated, over time this
extra pressure can increase your risk of a heart attack, stroke, kidney
disease and vascular dementia.
Schematic diagram showing the possible complication of hypertension.
Cardiovascular disease
High blood pressure can cause many
different diseases of the heart and blood vessels (medically known as cardiovascular diseases), including:
- stroke – when the blood supply to
part of the brain is cut off
- heart attack – when the supply of
blood to the heart is suddenly blocked
- embolism – when a blood clot or air
bubble blocks the flow of blood in a vessel
- aneurysm – when a blood vessel wall
bursts causing internal bleeding
- vascular dementia – when blood
flow to the brain is reduced, causing parts of the brain to become damaged.
Kidney disease
High blood pressure can also damage
the small blood vessels in your kidneys and stop them from working properly.
Mild to moderate chronic kidney disease does not usually cause any symptoms.
Kidney disease may need
treatment with a combination of medication and dietary changes. More serious cases may require dialysis (a treatment where waste
products are artificially removed from the body) or a kidney transplant.
Preventing high blood pressure
Having high blood pressure can be
prevented by eating healthily, maintaining a healthy weight, taking regular
exercise, drinking alcohol in moderation and not smoking.
Diet
Cut down on the amount of salt in
your food and eat plenty of fruit and vegetables. The eatwell plate 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 (for example, wholegrain rice, bread and pasta) and plenty of
fruit and vegetables helps lower blood pressure. Fruit and vegetables are full
of vitamins, minerals and fibre that keep your body in good condition. Aim to
eat five 80g portions of fruit and vegetables every day.
Alcohol
Regularly drinking alcohol above the recommended levels will raise your blood pressure over time. Staying within
the recommended levels is the best way to reduce your risk of developing
high blood pressure.
It is recommended that:
- men should not regularly drink more than three to four units a day
- women should not regularly drink more than two to three units a day.
Alcohol is also high in calories,
which will make you gain weight. This will also increase your blood pressure.
Weight
Being overweight forces your heart to
work harder to pump blood around your body, which can raise your blood
pressure. If you do need to shed some weight,
it is worth remembering that just losing a few pounds will make a big
difference to your blood pressure and overall health.
Exercise
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. For it to count, the activity should make
you feel warm and slightly out of breath. Someone who is overweight may only
have to walk up a slope to get this feeling. Physical activity can include
anything from sport to walking and gardening.
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.
Caffeine
Drinking more than four cups of
coffee a day may increase your blood pressure. If you are a big fan
of coffee, tea or other caffeine-rich drinks (such as cola and some energy
drinks), consider cutting down.
It is fine to drink tea and coffee as
part of a balanced diet but it is important that these drinks are not your only
source of fluid.
Source: NHS Choices.
Source: NHS Choices.