Blood Pressure High

 

Overview

The heart is a muscle that is designed to pump a constant supply of blood around the body.

The heart pumps blood that is low in oxygen towards the lungs, where it will receive more oxygen.

The heart also pumps oxygen-rich blood around the body so that oxygen can be used by the muscles and the cells in your body.

There are two measurements used to assess blood pressure:

  • Systolic pressure is the blood pressure that is exerted when the heart beats and forces blood around the body.
  • Diastolic pressure is the measure of blood pressure when the heart is resting between beats.

Blood pressure is defined as the amount of pressure exerted on the walls of the arteries as the blood moves through them. It is measured in millimetres of mercury (mmHg). Both the systolic and diastolic pressures are measured, and these figures are usually represented with the systolic pressure first, followed by the diastolic pressure.

So if your GP says that your blood pressure is ‘120 over 80’, or 120/80mmHg, what they mean is that you have a systolic pressure of 120mmHg and a diastolic pressure of 80mmHg.

High blood pressure (hypertension)

High blood pressure (hypertension) is usually defined as having a sustained blood pressure of 140/90mmHg or above.

High blood pressure often causes no symptoms or immediate problems, but it is a major risk factor for developing a serious cardiovascular disease (conditions that can affect the circulation of blood around the body), such as a stroke or heart disease.

If you have high blood pressure, your heart has to work harder to pump blood around your body. Over time, this can weaken it. Also, the increased pressure can damage the walls of your arteries, which can result in a blockage or cause the artery to split (haemorrhage). Both of these situations can cause a stroke.

Who is affected by high blood pressure?

High blood pressure is common, with 40% of adults in England having the condition. The number of people who have high blood pressure increases with age. For reasons that are not entirely understood, people of Afro-Caribbean and South Asian (India, Pakistan and Bangladeshi) origins are more likely to develop high blood pressure than other ethnic groups.

In 95% of cases, there is no single identifiable reason for a raise in blood pressure. However, all available evidence shows that your lifestyle plays a significant role in regulating your blood pressure. Risk factors for high blood pressure include:

  • Age.
  • Excessive alcohol consumption.
  • Poor diet.
  • Lack of exercise.
  • Obesity.

High blood pressure can be treated or prevented by making changes to your lifestyle, such as exercising more regularly, eating a healthier diet and cutting back on your consumption of alcohol. Medicines are also available that can help lower your blood pressure

 

Complications

Cardiovascular disease

If left untreated, high blood pressure can cause many different types of cardiovascular disease, such as a stroke, heart attack, blood clot or aneurysm (a swollen, or burst, blood vessel).

Kidney disease

High blood pressure can damage the small blood vessels in your kidneys which can stop them working properly. This can cause a number of symptoms including:

  • tiredness,
  • swollen ankles, feet, or hands (due to water retention),
  • shortness of breath,
  • blood and/or protein in your urine,
  • an increase need to urinate, particularly at night, and
  • itchy skin.

Kidney disease can be treated using a combination of medicines and dietary supplements. More serious cases may require dialysis (a treatment where waste products are artificially removed from the body), or a kidney transplant.

Causes

There are two types of high blood pressure:

  • essential (or primary) high blood pressure – where there is no identifiable cause, and
  • secondary high blood pressure – where high blood pressure is the result of an underlying cause, such as kidney disease, or a particular type of medication that you are taking.


Essential high blood pressure

While the cause of essential high blood pressure remains unknown, there is compelling evidence to show that there are number of risk factors which increase your chances of developing the condition. These risk factors 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 Afro-Caribbean or South Asian origin,
  • obesity,
  • lack of exercise,
  • smoking,
  • excessive alcohol consumption,
  • high amount of salt in your diet,
  • high fat diet, and
  • stress.

A number of other medical conditions have also been linked to an increase chance in developing essential high blood pressure, such as diabetes and kidney disease.

Secondary high blood pressure

A small amount of cases of high blood pressure (approximately 5%) are the result of an underlying condition or cause. These include:

  • kidney conditions, such as a kidney infection, or kidney disease,
  • narrowing of the arteries,
  • hormonal conditions, such as Cushing’s syndrome (a condition where your body produces an excess of steroid hormones),
  • conditions affecting the tissue of the body, such as lupus (a condition where your immune system attacks healthy tissue),
  • medicines, such as the oral contraceptive pill, or the type of painkillers known as nonsteriodal anti-inflammatory drugs (NSAIDs), such as ibuprofen,
  • excessive alcohol consumption, and
  • illegal stimulants, such as cocaine, amphetamine and crystal meth.

Diagnosis

Sphygmomanometer

Blood pressure is often measured using a device known as a sphygmomanometer. This device uses an inflatable cuff, and has a scale of mercury like a thermometer.

The cuff is pumped up to restrict the flow of blood in your arm, before slowly being released. The person checking your blood pressure will use a stethoscope to listen to your pulse.

Hearing how your pulse reacts after the cuff is released allows a measurement to be taken on the scale of mercury, giving an accurate reading of your blood pressure.

Many GPs surgeries now use a digital sphygmomanometer, where your pulse is measured using electrical sensors. Blood pressure testing kits are also commercially available.

Checking your blood pressure

Having one high reading does not necessarily mean that you have high blood pressure. Your blood pressure can fluctuate throughout the day, and if you feel anxious or stressed when you visit your GP, it may lead to an increase in blood pressure.

Therefore, your GP will need to take several readings over a set period of time, usually every month, to see if your blood pressure level is consistently high.

Blood and urine tests may also be carried out in order to check for any condition known to cause a rise in blood pressure, such as a kidney infection.

You may also be given a blood pressure kit to take home with you so that you can monitor your levels throughout the day.

Treatment

Treatment for high blood pressure will depend on your blood pressure levels and your associated risk of developing a cardiovascular disease, such as a stroke.

There are seven main risk factors for developing a cardiovascular disease. These are:

  • age,
  • high blood pressure,
  • smoking (or a previous history of smoking),
  • obesity,
  • lack of exercise,
  • having a high level of cholesterol in your blood, and
  • having a family history of cardiovascular disease.

If your blood pressure is slightly high and your GP feels that the risks of cardiovascular disease are low, you should be able to get your blood pressure under control by making some simple changes to your lifestyle, such as modifying your diet and taking regular exercise.

If your blood pressure is moderately high, or your GP feels that your risks of developing a cardiovascular disease in the next ten years is higher than one in five, you will be given medicines, as well as being advised to make changes to your lifestyle.

If your blood pressure is severely high (180/110 mmHg or above) you will be referred to a specialist in the treatment of high blood pressure.

Changes in lifestyle

The following changes in lifestyle are known to reduce blood pressure:

  • regular exercise of at least 30 minutes a day, five times a week,
  • moderating your alcohol intake to recommended levels (less than 21 units per week for men; and less than 14 units per week for women),
  • eating a low-fat, balanced, healthy diet,
  • restricting your consumption of salt to less than 6g (0.2oz) a day,
  • losing weight if you are overweight or obese,
  • restricting caffeine consumption to less than five cups of coffee or tea a day, and
  • relaxation therapies, such as meditation.

It should be stressed that even achieving a relatively low drop in blood pressure can have significant health benefits. For example, a reduction of 5 mmHg in your diastolic blood pressure will reduce the chances of you having a stroke by 34%, and of developing heart disease by 20%.

See the ‘prevention’ section for more information about the possible changes that you can make to your lifestyle in order to lower your blood pressure.

Medicines

There are a number of medicines that can be used to treat high blood pressure. You may be given a combination of different medicines to take to bring your blood pressure under control.

For many people with high blood pressure, it is recommended that they take blood pressure lowering medicines for the rest of their lives. However, if your blood pressure levels remain under control for several years, it may be possible to discontinue treatment.

The most widely used medicines for treating high blood pressure are outlined below.

Angiotensin-converting enzyme (ACE) inhibitors

Angiotensin-converting enzyme (ACE) inhibitors work by blocking the actions of some of the hormones that help regulate blood pressure. By stopping these hormones from working, the medicines help reduce the amount of water in your blood and also widen your arteries, both of which will bring your blood pressure down.

ACE inhibitors are not suitable for pregnant or breastfeeding women, people with conditions that affect the blood supply to their kidneys, or people with a history of heart disease.

ACE inhibitors have been known to reduce the supply of blood to the kidneys which can reduce their efficiency. Therefore, blood and urine tests may be carried out before you start taking ACE inhibitors to make sure that there are no pre-existing problems with your kidneys.

Annual blood and urine tests may be required if you continue to use ACE inhibitors.

Side effects of ACE inhibitors include:

  • dizziness,
  • tiredness or weakness,
  • headaches, and
  • a persistent dry cough.

Most of these side effects should pass in a few days, although some people find that they continue to have a dry cough.

If side effects become troubling, a medicine that works much in a similar way to ACE inhibitors, known as an angiotensin-2 receptor antagonist, may be recommended.

ACE inhibitors can cause unpredictable effects if taken with other medications, including over-the-counter (OTC) medicines. Check with your GP or pharmacist before taking anything in combination with this medicine.

Calcium channel blockers

Calcium channel blockers work by relaxing the muscles that make up the walls of your arteries. This causes your arteries to widen, reducing your blood pressure.

Calcium channel blockers are not recommended for people with a history of heart disease, liver disease, or circulation problems. Side effects of calcium channel blockers include:

  • flushed face,
  • headaches,
  • swollen ankles,
  • dizziness,
  • tiredness, and
  • skin rashes.

However, these side effects should pass within a few days, once your body gets used to the medicine.

You should not drink grapefruit juice if you are taking calcium channel blockers because this can cause a drop in your blood pressure.

Thiazide diuretics

Thiazide diuretics work by reducing the amount of water in your blood, and widening the walls of your arteries. They are not recommended for pregnant women, or people who have gout.

Thiazide diuretics have been known to reduce the level of potassium in your blood, which can interfere with your heart and kidney functions. They can also raise the level of sugar in your blood which could lead to diabetes.

Therefore, you will probably be recommended to have blood and urine tests every six months so that your potassium and blood sugar levels can be monitored.

A few people have reported that they could not get, or maintain, an erection while taking thiazide diuretics, but this particular side effect was resolved once the medicines were withdrawn.

Beta-blockers

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 proved successful. This is because beta-blockers have more potential side effects than the other medicines that are used to treat high blood pressure.

Beta-blockers work by slowing down your heart rate, and the force of your heart. This reduces the pressure at which the blood is pumped out of your heart and around your body.

Common side effects of beta-blockers include:

  • tiredness,
  • cold hands and feet,
  • slow heartbeat, and
  • diarrhoea and nausea.

Less common side effects of beta-blockers include:

  • sleep disturbances,
  • nightmares, and
  • impotence.

Beta-blockers can also interact with other medicines, causing possible adverse side effects. You should check with your GP or pharmacist before taking other medicines in combination with beta-blockers.

Medicines and ethnic groups

Research has shown that different blood pressure lowering medicines work better for different ethnic groups. For example, ACE inhibitors are a more effective as a first choice medicine for treating high blood pressure in white people, whereas calcium channel blockers, or thiazide diuretics, tend to work better as a first choice medicine for black people.

It is thought that this is due to the fact that black people tend to have a lower level of renin in their blood. Renin is an enzyme that helps to regulate blood pressure. ACE Inhibitors work best where there is a high level of renin in the blood, so they often prove not as effective in treating black people with high blood pressure.

Your GP will therefore take into account your ethnic background when drawing up your treatment plan.

Prevention

The best way to prevent high blood pressure, and the associated risks of cardiovascular disease, is to eat a healthy diet, maintain a healthy weight, exercise regularly, drink alcohol in moderation, and avoid smoking.

Diet

A low fat, high fibre diet is recommended, including plenty of fresh fruit and vegetables (five portions a day) and whole grains. You should limit the amount of salt that you eat to no more than 6g (0.2oz) a day because too much salt will increase your blood pressure. 6g of salt is about one teaspoonful.

You should avoid foods that are high in saturated fat because this will increase your cholesterol level, which is another risk factor for cardiovascular disease.

Foods high in saturated fat include:

  • meat pies,
  • sausages, and fatty cuts of meat,
  • butter,
  • ghee – a type of butter that is often used in Indian cooking,
  • lard,
  • cream,
  • hard cheese,
  • cakes and biscuits, and
  • foods that contain coconut, or palm oil.

However, eating some food high in unsaturated fat can actually decrease your cholesterol level.

Foods high in unsaturated fat include:

  • oily fish,
  • avocados,
  • nuts and seeds,
  • sunflower, rapeseed and olive oil


Weight

Being overweight is a risk factor for having high blood pressure, and your risk is increased further if you are obese.

The most scientific way to measure your weight is to calculate your Body Mass Index (BMI). This is your weight in kilograms divided by your height in metres squared. In the UK, people with a BMI of between 25-30 are overweight, and those with an index above 30 are classed as obese. People with a BMI of 40 or more are morbidly obese.

The best way of tackling obesity is to reduce the amount of calories that you eat, and ensure that you take regular exercise. Your GP will be able to provide you with further information and advice about how you can do this.

Symptoms

High blood pressure does not normally cause any symptoms until it has reached a very high level – typically 180/110 mmHg. Symptoms that your blood pressure has reached a very high level include:

  • a headache that lasts for several days,
  • nausea,
  • dizziness,
  • drowsiness,
  • blurred, or double vision,
  • nosebleeds,
  • irregular heartbeat (palpitations), or
  • shortness of breath.

If you experience any of these symptoms, you should see your GP as soon as possible.

If you are diagnosed with high blood pressure, it is very important for you to have your blood pressure checked on a regular basis. Adults should have their blood pressure checked at least once every five years although, ideally, it should be checked more frequently, particularly if you have any contributory risk factors.

Most GP surgeries and clinics operate a policy where they will arrange for you to have regular blood pressure checks, and they are also available on request. Children will normally have their blood pressure routinely tested as part of their regular health check-ups.