What is high blood pressure?
Blood pressure is recorded with 2 numbers. The systolic pressure (higher number) is the force at which your heart pumps blood around your body.
The diastolic pressure (lower number) is the resistance to the blood flow in the blood vessels. They’re both measured in millimetres of mercury (mmHg).
As a general guide:
- high blood pressure is considered to be 140/90mmHg or higher
- ideal blood pressure is considered to be between 90/60mmHg and 120/80mmHg
- low blood pressure is considered to be 90/60mmHg or lower
A blood pressure reading between 120/80mmHg and 140/90mmHg could mean you’re at risk of developing high blood pressure if you don’t take steps to keep your blood pressure under control.
Who’s at risk of high blood pressure?
Factors that can raise your risk of developing high blood pressure include:
- age – the risk of developing high blood pressure increases as you get older
- a family history of high blood pressure
- being of African or Caribbean origin
- a high amount of salt in your food
- a lack of exercise
- being overweight or obese
- regularly drinking large amounts of alcohol
- long-term sleep deprivation
Making healthy lifestyle changes can help keep your blood pressure at a normal level.
Known causes of high blood pressure
In about 1 in 20 cases, high blood pressure occurs as the result of an underlying condition, medication or drug.
Conditions that can cause high blood pressure include:
- kidney disease
- long-term kidney infections
- obstructive sleep apnoea – a condition in which the walls of the throat relax and narrow during sleep, interrupting normal breathing
- glomerulonephritis – damage to the tiny filters inside the kidneys
- narrowing of the arteries supplying the kidneys
- hormone problems – such as an underactive thyroid, an overactive thyroid, Cushing’s syndrome, acromegaly, increased levels of the hormone aldosterone (hyperaldosteronism) and phaeochromocytoma
- lupus – a condition in which the immune system attacks parts of the body such as the skin, joints and organs
- scleroderma – a condition that causes thickened skin, and sometimes problems with organs and blood vessels
Medicines and drugs that can increase your blood pressure include:
- the combined oral contraceptive pill
- steroid medication
- non-steroidal anti-inflammatory drugs (NSAIDs) – such as ibuprofen and naproxen
- some over-the-counter cough and cold remedies
- some herbal remedies – particularly those containing liquorice
- some recreational drugs – such as cocaine and amphetamines
- some selective serotonin-noradrenaline reuptake inhibitor (SSNRI) antidepressants – such as venlafaxine
In these cases, your blood pressure may return to normal once you stop taking the medicine or drug.
When treatment is recommended
Everyone with high blood pressure is advised to make healthy lifestyle changes.
Whether medication is recommended depends on your blood pressure reading and your risk of developing problems such as heart attacks or strokes.
Your doctor will carry out some blood and urine tests, and ask questions about your health to determine your risk of other problems:
- if your blood pressure is consistently above 140/90mmHg (or 135/85mmHg at home) but your risk of other problems is low – you’ll be advised to make some changes to your lifestyle
- if your blood pressure is consistently above 140/90mmHg (or 135/85mmHg at home) and your risk of other problems is high – you’ll be offered medication to lower your blood pressure, in addition to lifestyle changes
- if your blood pressure is consistently above 160/100mmHg – you’ll be offered medication to lower your blood pressure, in addition to lifestyle changes
There 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, while others may take longer.
- cutting your salt intake to less than 6g (0.2oz) a day – find out how you can reduce the amount of salt in your diet
- eating a low-fat, balanced diet – including plenty of fresh fruit and vegetables; get tips on eating more healthily
- being active – read some tips about getting more exercise
- cutting down on alcohol – get tips on cutting down, including downloading a drinks diary and keeping track of your drinking
- losing weight – find out what your ideal weight is using the BMI healthy weight calculator and read advice about losing weight if you’re overweight
- drinking less caffeine – found in coffee, tea and cola
- stopping smoking – get help quitting
- getting at least 6 hours of sleep a night if you can – read some tips for getting to sleep
You can take these steps today, regardless of whether or not you’re taking blood pressure medication. In fact, by making these changes early on you may be able to avoid needing medication.
Medication for high blood pressure
Several medications can be used to help control high blood pressure. Many people need to take a combination of different medicines.
The medication recommended for you at first will depend on your age and ethnicity:
- if you’re under 55 years of age – you’ll usually be offered an ACE inhibitor or an angiotensin-2 receptor blocker (ARB)
- if you’re aged 55 or older, or you’re any age and of African or Caribbean origin – you’ll usually be offered a calcium channel blocker
You may need to take blood pressure medication for the rest of your life. But your doctor might be able to reduce or stop your treatment if your blood pressure stays under control for several years.
It’s really important to take your medications as directed. If you miss doses, it won’t work as effectively. The medication won’t necessarily make you feel any different, but this doesn’t mean it’s not working.
Medications used to treat high blood pressure can have side effects, but most people don’t experience any. If you do, changing medication will often help.
High blood pressure can often be prevented or reduced by eating healthily, maintaining a healthy weight, taking regular exercise, drinking alcohol in moderation and not smoking.
Cut down on the amount of salt in your food and eat plenty of fruit and vegetables. The Eatwell Guide 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 – such as wholegrain rice, bread and pasta – and plenty of fruit and vegetables also helps lower blood pressure. Aim to eat 5 portions of fruit and vegetables every day.
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’s worth remembering that just losing a few pounds will make a big difference to your blood pressure and overall health.
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.
Physical activity can include anything from sport to walking and gardening
Cut down on caffeine
Drinking more than 4 cups of coffee a day may increase your blood pressure.
If you’re a big fan of coffee, tea or other caffeine-rich drinks, such as cola and some energy drinks, consider cutting down.
It’s fine to drink tea and coffee as part of a balanced diet, but it’s important that these drinks are not your main or only source of fluid.
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.
Get a good night’s sleep
Long-term sleep deprivation is associated with a rise in blood pressure and an increased risk of hypertension. It’s a good idea to try to get at least 6 hours of sleep a night if you can.