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High Blood Pressure (Hypertension)
High Blood Pressure (Hypertension)
Introduction
Do you know what your blood pressure is? Most of us don’t give a thought to our blood pressure until it causes us problems. High blood pressure, also known as hypertension, can lead to serious health conditions, which is why it’s a figure you need to know.
- What is blood pressure?
- How is blood pressure measured?
- What do the readings mean?
- Why is it important?
- What are my chances of having it?
- Factors that increase your risk of having high blood pressure
- Take the test
- Factors that can change your blood pressure
- Treatment for high blood pressure
- Drug treatments
- Commonly prescribed hypertension drugs
- Medicines and ethnicity
- Side-effects
- Never just stop taking your medicine without talking to your doctor first
- How to prevent high blood pressure
What is blood pressure?
Our blood moves around our bodies through a network of arteries and veins, delivering oxygen, essential nutrients and hormones and carrying away waste products. It’s the beating of your heartthat keeps blood moving.
With each beat, your heartpumps blood through your arteries, creating blood pressure inside them. With each contraction of your heart, your blood pressure goes up – this is known as the systolic pressure.
In between beats, when your heart is resting, your blood pressure goes down. This is known as the diastolic pressure.
How is blood pressure measured?
Blood pressure is measured in millimetres of mercury (mmHg). When you have your blood pressure taken, you’ll be told the result as two figures. The first number is the systolic pressure, while the second is the diastolic pressure.
What do the readings mean?
- Equal to or less than 120 over 80 means your blood pressure is normal and healthy
- Above 120 over 80 up to 139 over 89 means that you are pre-hypertensive
- Consistently above 140 over 90 during a number of weeks – you have Stage 1 hypertension
- Consistently above 160 over 100 or higher during a number of weeks – you have Stage 2 hypertension
The National Institute of Health and Clinical Excellence give the following guidance to doctors: patients should have a reading of under 140/90 mmHg to be considered normotensive (normal blood pressure). If a patient’s blood pressure is consistently 140/90mmHg or above when they have it measured, then they have hypertension. This is true even when only one of the figures is high – for instance if a patient’s systolic pressure is 140 or over, or if their diastolic pressure is 90mmHg or over.
If you have diabetes, kidney disease, or have had a stroke or heart attack, your doctor may want you to aim for a reading of 130/80 mmHg or below.
Why is it important?
The higher your blood pressure, the worse it is for your health and can cause potentially life-threatening conditions.
High blood pressure puts you at greater risk of developing narrowed arteries, which then puts you at increased risk of having a stroke, heart attack, heart failure, kidney failure and sight problems.
Because high blood pressure rarely causes any symptoms (although it can sometimes cause breathlessness, headaches, nosebleeds, confusion and sight problems), this is something you can’t leave to chance.
What are my chances of having it?
High blood pressure is a common condition in both men and women and increases in frequency as you grow older. Many people in the UK do not realise they have the condition. In fact, high blood pressure remains poorly controlled in the UK, compared with other developed countries.
The cause of high blood pressure is not known in most cases and is called essential hypertension. Blood pressure inside the arteries depends on how hard the heart works and how flexible the arteries are.
Slight narrowing of the arteries is thought to increase blood pressure, but the reasons for the increase are probably due to a number of factors.
Factors that increase your risk of having high blood pressure:
- Eating too much salt
- Being overweight
- Poor diet – eating too much saturated fat increases the chances of developing fatty plaques in the arteries (atherosclerosis) and increasing blood pressure
- Not getting enough exercise
- Drinking too much alcohol
- Smoking
- Belonging to certain ethnic groups. British people of Indian, Pakistani, Bangladeshi, African and Caribbean origin are more likely to have high blood pressure
- Having high cholesterol levels also increases the chances of serious consequences from high blood pressure
- Getting older – your blood pressure rises with age
- Being stressed – although this may only affect your blood pressure for a short time
- Hereditary factors can make a difference, too. If one or both your parents have high blood pressure, this increases your risk of developing it
- Chronic kidney disease, diabetes, adrenal and thyroid disorders
Take the test
The only way to find out if you have high blood pressure is to have it tested. The NHS recommends that adults have their blood pressure checked every five years and preferably more often, particularly if you have any contributory risk factors.
If your blood pressure is high, you need to have it checked more frequently by visiting your GP’s surgery. Your doctor or nurse will measure it using an automatic digital machine, which will give a read-out of your results.
The test will involve having an inflatable cuff fitted around your upper arm. You’ll feel some pressure on your arm as the cuff tightens around it as it is inflated, but it doesn’t hurt, and only lasts a short while.
There is also an older style of equipment, called a sphygmomanometer. This works in a similar way to the digital machine, but your nurse or GP will pump up the cuff around your arm manually, listen to the sounds of your blood-flow through a stethoscope and read the results from measurements.
Your blood pressure changes throughout the day, depending on what you’ve been doing, and on the time of day. It is at its lowest when you’re asleep, or when your muscles are totally relaxed.
Factors that can change your blood pressure
Standing up, being physically active and stressed or anxious can all push up your blood pressure. You should try to have it tested at the same time of day, under the same conditions, every time.
For some people, just the pressure of having a test is enough to push it up. If your GP or nurse thinks this is affecting you, they may suggest that you take your own test at home. Ask your doctor or nurse if they think this would be a good idea for you.
If you have one high reading, you’ll be asked to come back a couple of times to have further readings. This is to make sure that your high reading wasn’t caused by stress on that first appointment. You may be asked to wait at your surgery for a while and have your reading taken again on the same day, particularly if it was quite high.
If your blood pressure is high your doctor may carry out some additional tests, such as having your blood pressure taken when you are walking (ambulatory blood pressure). They may ask you about your family and medical history. They may also carry out urine and blood tests and an ECG, which measures the electrical activity in your heart.
The information from these tests will help to give your doctor a better over-all picture of your health, and establish whether your blood pressure has affected your health.
Treatment for high blood pressure
High blood pressure can’t usually be cured, but it can be treated, using a combination of self-help measures and medication.
If your blood pressure is 140/90 to 160/100mmHg, you’ll be advised to do the following:
- Lose weight. If you’re
overweight you’ll be aiming to reach the recommended weight for your
height
- Stop smoking
- Cut back on your alcohol
intake if you drink too much
- Be more
physically active – aim for 30 minutes of moderate activity at least five
times a week
- Eat at least five different types of fruit and vegetables a day
- Reduce the amount of salt you eat
If your blood pressure isn’t too high, making these changes can be enough to bring it down to a healthy level. In certain circumstances – if you are an older person or smoke or have high cholesterol – you may also be given medicine to help bring your blood pressure down.
Drug treatments
There are a number of different hypertensive medicines and you may be given a combination of them to help control your blood pressure. You may have to take them for rest of your life. However, if your blood pressure levels remain under control for several years, you may be able to stop taking them.
Commonly prescribed hypertension drugs:
Angiotensin-converting enzyme (ACE) inhibitors block the actions of some of the hormones which regulate blood pressure to reduce the amount of water in your blood and widen your arteries. Examples are enalapril, lisinopril, ramipril, perindopril and trandolapril.
Angiotensin Receptor Blockers (ARB) block the chemical receptors for angiotensin II on the small arteries (arterioles), preventing them from narrowing (constricting), widening the arteries and lowering blood pressure. Examples are irbesartan, candesartan, losartan and valsartan.
Calcium channel blockers(CCB) relax the muscle walls of your arteries, making them wider and thus reducing your blood pressure. Examples are verapamil, nifedipine, nicardipine, amlodipine, felodipine, diltiazem and nimodipine.
Thiazide diuretics reduce the amount of water in your blood and widen the walls of your arteries. Examples are bendroflumethiazide, chlortalidone, benzthiazide, clopamide cyclopenthiazide, hydrochlorothiazide, xipamide, indapamide, hydroflumethiazide and metolazone.
Beta-blockers slow down your heart rate and reduce the pumping force of your heart, which lowers the pressure at which the blood is pumped out of your heart and around your body. Examples are acebutalol, atenolol, betaxolol, bisoprolol, carvedilol, celiprolol, esmolol, labetalol, metoprolol, nadolol, nebivolol, oxprenolol, pindolol , sotalol, propranolol and timolol.
Medicines and ethnicity
Different ethnic groups respond in different ways to each hypertension drug. ACE inhibitors, for example, are more effective at treating high blood pressure in white people, while calcium channel blockers and thiazide diuretics work better in black people.
Research suggests that black people have lower levels of the blood pressure-regulating enzyme renin in their bloodstream. ACE Inhibitors work best when there is a high level of this enzyme in the blood, so work less well in black people.
Your GP will take into account your ethnic background when drawing up your treatment plan.
Side-effects
If you find you are experiencing side-effects from your tablets, talk to your doctor to see if there’s an alternative medicine you could take. Remember to read the leaflet inside your medication to find out what side-effects can occur or ask your doctor to explain what they are and what you should do if you experience them.
Never just stop taking your medicine without talking to your doctor first.
Your blood pressure will be checked regularly, to see if it has come down. Once your blood pressure is under control, your GP may try reducing medication, while keeping an eye on the readings.
More information about side-effects of blood pressure medication can be found the NHS Library.
How to prevent high blood pressure
You can take steps to help prevent high blood pressure developing. These are the same lifestyle changes that you would make if you were trying to bring it down. Making these changes before it reaches unhealthy levels would be good for your overall health too:
- If you are overweight, lose weight
- Stop smoking
- Cut back on alcohol
- Be more physically active
- Eat at least five different types of fruit and vegetables a day
- Cut back on salt
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References:This article has been written for PruHealth by Dr Foster Research. All Dr Foster Research (DFR) health content is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional.
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