Hypertension
High blood pressure (hypertension)
About high blood pressure
High blood pressure, also known as hypertension, is usually defined as having a sustained blood pressure of 140/90mmHg or above.
The line between normal and raised blood pressure is not fixed and depends on your individual circumstances. However, most doctors agree that the ideal blood pressure for a physically healthy person is around 120/80mmHg.
A normal blood pressure reading is classed as less than 130/80mmHg.
The heart (blood pump)
The heart is a muscle that is designed to constantly pump blood around the body. It pumps blood that is low in oxygen towards the lungs, through the venous 'pipeline' (veins), where it receives a fresh supply of oxygen.
Once the blood is fully oxygenated, the heart pumps the oxygen-rich blood around the body so that the oxygen can be used by the body’s muscles and cells, through the arterial 'pipeline' (arteries).
How is blood pressure measured?
Blood pressure is defined as the amount of pressure that is exerted on the artery walls as blood moves through them. It is measured in millimeters of mercury, or mmHg.
A more detailed explanation is provided below.
Two measurements are used to measure blood pressure:
Both the systolic and diastolic pressures are measured in millimeters of mercury (mmHg).
The figures are usually represented with the systolic pressure first, followed by the diastolic pressure. Therefore, if your GP says that your blood pressure is '120 over 80', or 120/80mmHg, they mean that you have a systolic pressure of 120mmHg and a diastolic pressure of 80mmHg.
More about the diagnosis of high blood pressure
Symptoms of high blood pressure
High blood pressure often causes no symptoms or immediate problems.
The only way to find out whether you have high blood pressure is to have your blood pressure checked regularly. Ask your GP when you are next due for yours to be checked.
Find out more about the symptoms of high blood pressure
How common is high blood pressure?
High blood pressure is a common condition, it is estimated that 18% of adult men and 13% of adult women have high blood pressure but are not getting treatment for it.
In 90-95% of cases, there is no single identifiable reason for a rise in blood pressure. But all available evidence shows that lifestyle plays a significant role in regulating your blood pressure.
Risk factors for high blood pressure include:
Also, for reasons not fully understood, people of Afro-Caribbean and South Asian origin (Indian, Pakistani, and Bangladeshi) are more likely to develop high blood pressure than other ethnic groups.
More about the causes of high blood pressure and how high blood pressure is prevented
What's the impact of having high blood pressure?
High blood pressure is a major risk factor for developing cardiovascular diseases such as:
Diabetes and kidney disease are also linked to high blood pressure complications.
More about complications of high blood pressure
Treatment and prevention of high blood pressure
High blood pressure can be managed or controlled by making changes to your lifestyle, such as:
Medication that can help you lower your blood pressure is also available.
Symptoms of high blood pressure
High blood pressure does not usually cause any obvious symptoms. Symptoms can occur in rare cases where a person has a very high blood pressure level so it is good to be aware of these.
The symptoms may include:
Visit your GP as soon as possible if you have any of these symptoms.
Regular blood pressure checks for over over 40's
The only way to find out whether you have high blood pressure is to have your blood pressure checked regularly. Ask your GP when you are next due for yours to be checked.
Blood pressure checks are usually available on request at most GP surgeries and health clinics. Some surgeries have home monitoring devices available, which you may be able to use at the time of blood pressure medication start-up or change. Many also have a policy of arranging regular checks for you.
Adults who are over 40 and have not been diagnosed with high blood pressure should have their blood pressure checked at least once every five years. However, your blood pressure should ideally be checked more frequently, particularly if you have any contributory risk factors.
Regular blood pressure checks if diagnosed with high blood pressure
If you are diagnosed with high blood pressure, your blood pressure will need to be closely monitored until it is brought under control.
After your blood pressure has been controlled, your GP or practice nurse will measure your blood pressure at agreed regular intervals (at least once a year).
It is important you attend these appointments to ensure your blood pressure is being maintained within an acceptable range.
Blood pressure checks during pregnancy
If you are pregnant, you should have your blood pressure checked on a regular basis, even if it is not 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).
Causes of high blood pressure
There are two types of high blood pressure:
You can find out more about each of these below.
Primary high blood pressure
While the specific cause of primary high blood pressure remains unknown, there is compelling evidence to suggest that a number of risk factors increase your chances of developing the condition.
These risk factors include:
A number of health conditions, such as diabetes and kidney disease, have also been linked to an increased risk of developing primary high blood pressure.
Secondary high blood pressure
Some cases of high blood pressure (between 5 and 10%) are the result of underlying factors or causes and this is known as secondary high blood pressure.
Underlying factors include:
Occasionally, a rise in blood pressure can result from taking herbal remedies, such as herbal supplements.
Diagnosing high blood pressure
The only way to find out whether you have high blood pressure is to have your blood pressure checked regularly. Ask your GP when you are next due for yours to be checked.
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 and not talking when the reading is taken.
Having one high blood pressure reading does not necessarily mean that you have high blood pressure. Your blood pressure can change throughout the day. Feeling anxious or stressed when you visit your GP can raise your blood pressure (often referred to as ‘white coat syndrome’).
Therefore, your GP will need to take several readings over a set period of time, usually every month, to see whether your blood pressure level is consistently high.
Blood and urine tests may also be carried out in order to check for conditions that are known to cause an increase in blood pressure, such as kidney infections.
You may also be given a blood pressure device to take home so that you can record your blood pressure level throughout the day. This also helps to identify white coat syndrome and therefore helps to identify the best treatment options for you.
Sphygmomanometer
Blood pressure is traditionally measured using a device known as a sphygmomanometer. This device uses an inflatable cuff and has a scale of mercury, like a thermometer.
Your pulse is heard by the health professional taking your blood pressure, through a stethoscope placed on your artery.
Digital sphygmomanometer
Many GP surgeries now use digital, or semi-automatic, sphygmomanometers which measure your pulse using electrical sensors in a cuff that is usually placed around your upper arm.
The cuff is pumped up to restrict the blood flow in your arm, before slowly being released.
Digital blood pressure device
Digital blood pressure devices are now commercially available
Treating high blood pressure
Treatment for high blood pressure will depend on your blood pressure levels and your associated risk (after taking account of several factors) of developing a cardiovascular disease, such as a heart attack or stroke.
There are seven main risk factors for developing cardiovascular disease. These are:
If your blood pressure is slightly high
If your blood pressure is slightly higher than the ideal level (120/80mmHg), and your GP feels that the risks of cardiovascular disease are low, then you should be able to lower your blood pressure by making simple lifestyle changes (see more below).
If your blood pressure is moderately high
If your blood pressure is moderately high (140/90mmHg or higher), or your GP feels that your risk of developing cardiovascular disease in the next 10 years is more than one in five, then you will be advised about changing your lifestyle and may also be prescribed medication.
If your blood pressure is very high
If your blood pressure is very high (180/110 mmHg or above) you should be referred to a hypertension specialist (a doctor who specializes in treating high blood pressure).
Lifestyle changes
The following lifestyle changes are known to reduce high blood pressure:
Even if you achieve a relatively low decrease in your blood pressure, it can still have significant health benefits.
More about preventing high blood pressure
Medication
A number of medications can be used to treat high blood pressure. You may need to take more than one type of medication to lower your blood pressure because a combination of treatments is sometimes needed to successfully treat the condition.
If you have high blood pressure, 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, you should ask your GP if you could come off your treatment and have your blood pressure monitored.
Most medications that are used to treat high blood pressure have some side effects (see below for details of the specific side effects of each type of medication). Consult your GP immediately if you have any of the following common side effects while taking medication for high blood pressure:
Research has shown that different blood pressure-lowering medications work better for different ethnic groups. For example, ACE inhibitors are more effective as a first-choice medication for treating high blood pressure in white people, whereas calcium channel blockers, or thiazide diuretics, tend to work better for black people.
It is thought that this is because 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 are most effective when there is a high amount of renin in the blood, so they are not as effective in treating black people with high blood pressure.
Therefore, your GP will consider your ethnic background when making a treatment plan.
The most widely used medications for treating high blood pressure are described below:
Angiotensin-converting enzyme (ACE) inhibitors
Angiotensin-converting enzyme (ACE) inhibitors work by blocking the actions of some of the hormones that help to regulate blood pressure.
By stopping these hormones from working, the medication helps to reduce the amount of water in your blood, and it widens your arteries, decreasing your blood pressure.
ACE inhibitors are not suitable for:
ACE inhibitors have been known to reduce the blood supply 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.
You may need to have annual blood and urine tests if you continue to use ACE inhibitors.
Side effects of ACE inhibitors include:
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 particularly troublesome, a medication that works 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 some over-the-counter (OTC) ones. Therefore, as with any prescribed medication always check with your GP or pharmacist before taking any 'over-the-counter medication in combination with those prescribed for you.
Calcium channel blockers
Calcium channel blockers work by relaxing the muscles that make up the walls of your arteries. This widens your arteries and reduces your blood pressure.
Examples of calcium channel blockers include:
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Every calcium channel blocker acts differently. Common side effects of calcium channel blockers should pass within a few days once your body gets used to the medication, these include:
Certain brands of calcium channel blockers may also cause constipation in some people.
Do not drink grapefruit juice if you are taking calcium channel blockers because it can lower 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 (a type of arthritis where crystals develop inside the joints).
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.
Examples of thiazide diuretics include:
The side effects of thiazide diuretics include:
A few people have reported that they could not get or maintain an erection while taking thiazide diuretics. However, this particular side effect was resolved once the medication was withdrawn.
There are two other types of diuretics available that you may be prescribed these are:
Alpha-blockers
Alpha-blockers are effective in reducing high blood pressure. However, they are not usually prescribed unless you are already taking other medication and your blood pressure is still high.
Alpha-blockers, work by preventing the muscles that line your blood vessels (alpha receptors) from being activated and tightening the muscles in the walls of your blood vessels. This enables the blood vessels to relax and open, making it much easier for blood to flow through them and lower your blood pressure.
Examples of alpha-blockers include:
Common side effects of alpha-blockers include:
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 medications 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.
Examples of beta-blockers include:
Common side effects of beta-blockers include:
Less common side effects of beta-blockers include:
Although beta-blockers are not the preferred method of treatment for high blood pressure, they may be considered for younger people if:
Beta-blockers can also interact with other medications, causing possible adverse side effects. Therefore, as with any prescribed medication always check with your GP or pharmacist before taking any 'over the counter' medication in combination with those prescribed for you
Do not suddenly stop taking beta-blockers without first consulting your GP. Stopping this medication suddenly will lead to serious side effects, such as a rise in blood pressure or chest pain caused by a reduction in oxygen to your heart muscle (angina).
Complications of high blood pressure
If left untreated, high blood pressure can cause many different types of cardiovascular disease.
For example:
Kidney disease
High blood pressure can damage the small blood vessels in your kidneys and stop them from working properly.
This can cause a number of symptoms, including:
Kidney disease can be treated using a combination of medication and dietary supplements. Cases that are more serious may require dialysis (a treatment where waste products are artificially removed from the body) or a kidney transplant.
Preventing high blood pressure
The best ways to prevent high blood pressure and the associated risks of cardiovascular disease are to:
You can find out more about each of these below.
Eat a healthy diet
A low-fat, high-fiber diet is recommended, including plenty of fresh fruit and vegetables (five portions a day) and whole grains.
Limit the amount of salt that you eat to no more than 6g (0.2oz) a day. Too much salt will increase your blood pressure (6g of salt is about one teaspoonful).
Avoid foods that are high in saturated fat as this will increase your cholesterol level, which is another risk factor for cardiovascular disease.
Foods that are high in saturated fat include:
However, eating some foods that are high in unsaturated fat can actually decrease your cholesterol level.
Foods that are high in unsaturated fat include:
More about eating a healthy balanced diet
Maintain a healthy weight
Being overweight is a risk factor for having high blood pressure, and your risk increases further if you are obese.
There are two ways to check if you are overweight:
SexEthnicityWaist size (increased risk)Waist size (severe risk)Male Over 94 cm (37 inches)Over 102 cm (40 inches)MaleSouth Asian Over 90 cm (35.5 inches)Female Over 80 cm (32 inches)Over 88 cm (35 inches)FemaleSouth Asian Over 80 cm (32 inches)
The best way to tackle obesity is by reducing the number of calories that you eat, and taking regular exercise. Your GP can provide you with further information and advice on how you can do this.
More about having a healthy weight
Exercise
Exercise can raise your blood pressure at the time of doing it but regular exercise at the right level for you can help to reduce your blood pressure and maintain a lower level.
The following information provides general advice about blood pressure and exercise:
More about keeping active
Drink alcohol in moderation
Drinking excessive amounts of alcohol will increase your blood pressure and raise the cholesterol levels in your blood.
Sticking to the recommended amounts of alcohol consumption is the best way to reduce your risk of developing high blood pressure.
The recommended daily limits of alcohol consumption are:
A unit of alcohol is equal to about half a pint of normal-strength lager, a small glass of wine, or a pub measure (25ml) or spirits.
More about drinking alcohol responsibly
Drink caffeine in moderation
It is important to restrict your daily intake of coffee or drinks that contain caffeine, such as soft drinks and cola.
Your blood pressure may increase if you drink more than four cups of coffee a day.
Stop smoking
If you smoke, there is plenty of help and support available to help you quit.
A note from Dr. ALAA MOHAMMED
Hypertension ، Detection, evaluation, and nonpharmacological intervention
Worldwide prevalence estimates for HTN may be as much as 1 billion.
7.1 million deaths per year may be attributable to hypertension
Definition:
It's a systolic blood pressure SBP>139 mmHg and/or Diastolic blood pressure > 89 mmHg, based on the average of two or more properly measured, seated BP readings.
On each of two or more office visits.
Accurate Blood pressure measurement:
The equipment should be regularly inspected and validated. The operator should be trained and regularly retrained
The patient must be properly prepared and positioned and seated quietly for at least 5 minutes in a chair
The auscultatory method should be used.
Caffeine, exercise, and smoking should be avoided.
An appropriately sized cuff should be used.
BP measurement
At least two measurements should be made and the average recorded.
Clinicians should provide patients with their specific BP numbers and the BP goal of their treatment.
Classifications:
Prehypertension
Types of hypertension:
To assess lifestyle and identify other cardiovascular risk factors or concomitant disorders that may affect prognosis and guide treatment
• To reveal identifiable causes of high BP
• To assess the presence or absence of target organ damage and CVD
Complications of prolonged uncontrolled HTN:
• Changes in the vessel wall leading to vessel trauma and atherosclerosis throughout the vasculature
• Target organ dysfunction and ultimately failure
• Damage to the blood vessels can be seen on fundoscopy.
Identifiable causes of HTN:
Management
• Adopt a DASH eating diet as effective as one medication
• Dietary sodium reduction
• Physical activity decreases time in sedentary behaviors
• Moderation of alcohol consumption
• Reduce portion sizes for meals and snacks
References.:
Harrison medical textbook, JNC report, hypertension‘s Canada’s guidelines 20