What is hypertension?

Hypertension, or high blood pressure, is a common condition that will catch up with most people who live into older age. Blood pressure is the force of blood pressing against the walls of your arteries. When it's too high, it increases the heart's workload and can cause serious damage to the arteries. Over time, uncontrolled high blood pressure increases the risk of heart disease, stroke and kidney disease.

Hypertension symptoms

High blood pressure is sometimes called a silent killer because it may have no outward symptoms for years. Around 18% of adult men and 13% of adult women have high blood pressure but are not getting treatment for it. Internally, it can quietly damage the heart, blood vessels, eyes, brain and kidneys if left untreated. It's a major risk factor for strokes and heart attacks.

What causes hypertension?

Normal blood pressure readings will fall below 120/80, while higher results over time can indicate hypertension. In most cases, the underlying cause of hypertension is unknown. The top number (systolic) shows the pressure when your heart beats. The lower number (diastolic) measures pressure at rest between heartbeats, when the heart refills with blood. Occasionally, kidney or adrenal gland disease can lead to hypertension.

Prehypertension: A warning sign

Prehypertension is where blood pressure is consistently just above the normal level, falling anywhere between 120 and 139 for systolic pressure or 80 to 89 for the diastolic pressure. People in this range have twice the risk of developing heart disease than those with a lower reading. Your doctor may recommend lifestyle changes to help lower your blood pressure.

The hypertension danger zone

You have high blood pressure if readings average 140/90 or higher - for either number - though you may still have no symptoms. This is why it's important to get your blood pressure checked on a regular basis as often as advised.

Who gets high blood pressure?

High blood pressure becomes more common for both men and women with increasing age. By the age of 75 years old half of people have hypertension. You have a greater risk if a close family member has high blood pressure or if you have diabetes. High blood pressure is also more common in people of African-Caribbean origin. Those who are overweight are also at greater risk.

Hypertension and race

People of African-Caribbean origin are more likely to develop hypertension - and to develop it at a younger age. Extra salt sensitivity could be one reason. In those who are genetically salt-sensitive just a half-teaspoon of salt can raise blood pressure by 5 mmHg. Diet and excessive weight can play a role, as well.

Hypertension and salt

Salt can raise blood pressure by causing the body to retain fluid, which leads to a greater burden on the heart. Government advice is that adults should consume no more than 6g of salt a day - around one full teaspoon. You'll need to check food labels and menus carefully.  Processed foods contribute up to 75% of our salt intake. Tinned soups and luncheon meats are prime suspects.

Hypertension and stress

Stress can make your blood pressure spike, but it's unclear whether it directly causes high blood pressure as an ongoing condition. However, stress may lead to other unhealthy habits, such as a poor diet, alcohol use or smoking, which can contribute to high blood pressure and heart disease.

Hypertension and weight

Being overweight places a strain on your heart and increases your risk of high blood pressure. That is why diets to lower blood pressure are often also designed to control calories. They typically call for cutting down fatty foods and sugars, while increasing fruit, vegetables, lean protein and fibre.  Even losing 10 lb (4.5 kg) can make a difference.

Hypertension and alcohol

Drinking too much alcohol can increase your blood pressure. The NHS recommends that men should not regularly have more than 3-4 units a day, and women should not regularly have more than 2-3 units a day. A pint of lager or glass of wine is 2.3 units.

Hypertension and caffeine

If caffeine can make you jittery, can it also raise your blood pressure? It might have a temporary effect, but studies haven't shown any link between caffeine and the development of hypertension. However, the NHS suggests restricting your caffeine consumption to less than five cups of coffee or tea a day to try and avoid blood pressure increases.

Hypertension and pregnancy

Gestational hypertension is a kind of high blood pressure that occurs in the second half of pregnancy. Without treatment, it may lead to a serious condition called pre-eclampsia that endangers both the mother and baby. The condition can limit blood and oxygen flow to the baby and can affect the mother's kidneys and brain. After the baby is born, the mother’s blood pressure usually returns to its normal level.

Hypertension and medicine

Cold and flu medicines that contain decongestants are one of several classes of medicine that can cause your blood pressure to rise. Others include NSAID painkillers such as ibuprofen, steroids, diet pills, contraceptive pills and some antidepressants. If you have high blood pressure, talk to your doctor about what medicines and supplements you are taking that may affect blood pressure.

‘White Coat’ hypertension

Some people only have a high blood pressure reading in a clinic or doctor's surgery, perhaps because they’re nervous. Some will only have high blood pressure readings sporadically. To get a more accurate reading, take your blood pressure at home, chart your readings, and share them with your doctor. It is also a good idea to bring in your home monitor for a check of the device and your technique. You doctor may suggest you use an ambulatory blood pressure monitoring device for 24 hours. This consists of wearing a blood pressure cuff attached to an automatic blood pressure machine which takes a series of readings during your normal daily life away from the stress of the surgery.

Hypertension and children

While hypertension is more often a problem for adults, even children can have high blood pressure. "Normal" blood pressure varies based on a child's age, height and sex, so your doctor will need to tell you if there is a concern. Children are at greater risk if they are overweight, have a family history of the illness and if they're of African-Caribbean descent.

Treatment: The DASH diet

You may be able to lower your blood pressure by switching to a better diet. The DASH diet - Dietary Approaches to Stop Hypertension - involves eating more fruit, vegetables, whole-grain foods, low-fat dairy products, fish, poultry and nuts. You should eat less red meat, saturated fats and sweets. Reducing salt in your diet can also have a significant effect.

Treatment: Exercise

Regular exercise helps lower your blood pressure. Adults should do at least 30 minutes of moderate-intensity exercise at least five days a week. That could include gardening, walking briskly, cycling or other aerobic exercise. Muscle-strengthening activities are recommended at least two days a week and should work all major muscle groups.

Treatment: Diuretics

Diuretics are one of the medication choices if diet and exercise changes aren't enough. Also called "water pills," they help the body shed excess salt and water to lower blood pressure. That means you'll urinate more often. Some diuretics may deplete your body's potassium, causing muscle weakness, leg cramps and fatigue. Some can increase blood sugar levels in people with diabetes. Erectile dysfunction is a less common side effect.

Treatment: Beta-blockers

Beta-blockers work by slowing the heart rate, which means that the heart doesn't have to work as hard. They are also used to treat other heart conditions, such as an abnormal heart rate called arrhythmia. They are less commonly used to treat blood pressure nowadays. Side effects can include insomnia, dizziness, fatigue, cold hands and feet, and erectile dysfunction.

Treatment: ACE inhibitors

ACE (angiotensin converting enzyme) inhibitors reduce your body's supply of angiotensin II, a substance that makes blood vessels contract and narrow. The result is more relaxed, open (dilated) arteries, as well as lower blood pressure and less effort for your heart. Side effects can include a dry cough, skin rash or dizziness and high levels of potassium. Women should not become pregnant while taking an ACE inhibitor.

Treatment: ARBs

Instead of reducing your body's supply of angiotensin II, ARBs (angiotensin II receptor blockers) block receptors for angiotensin, as if placing a shield over a lock. This blockade prevents angiotensin’s artery-tightening effects, and lowers your blood pressure. ARBs can take several weeks to become fully effective. Possible side effects include dizziness, muscle cramps, insomnia and high levels of potassium. Women should not become pregnant while taking this medication.

Treatment: Calcium channel blockers

Calcium channel blockers slow the movement of calcium into the cells of the heart and blood vessels. Since calcium causes stronger heart contractions, these medications ease the heart's contraction and relax the blood vessels. They can cause dizziness, heart palpitations, swelling of the ankles and constipation. Take them with food or milk and avoid grapefruit juice and alcohol because of possible interactions.

Treatment: Other medications

Other medications that relax the blood vessels include vasodilators, alpha blockers and central agonists. Side effects can include dizziness, a fast heart beat or heart palpitations, headaches or diarrhoea. Your doctor may suggest them if other blood pressure medications are not working well enough or if you have another condition.

Treatment: Complementary therapies

Meditation can put your body into a state of deep rest, which can lower your blood pressure. Yoga, tai chi, and deep breathing may also help. These relaxation techniques should be combined with other lifestyle changes, such as improved diet and regular exercise. Be aware that herbal therapies may interact with other medications you take, and some herbs actually raise blood pressure. Seek medical advice before taking herbal or other dietary supplements.

Living with high blood pressure

Hypertension is usually a life-long condition. It's important to take your medication and continue to monitor your blood pressure. If you keep it under control, you can reduce your risk of stroke, heart disease and kidney failure.

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