Hypertension (high blood pressure): readings, symptoms and treatment

Blood pressure is the force of blood against the walls of your arteries as your heart pumps. The British Heart Foundation explains that it is measured as two numbers: the systolic pressure, the higher number, when your heart pumps, and the diastolic pressure, the lower number, when the heart relaxes between beats.

Hypertension is when that pressure is persistently too high, even when you are resting. The BHF says it makes arteries lose their stretchiness and become stiff or narrow, which makes it easier for fatty material to build up. The NHS says that puts extra strain on your blood vessels, heart and other organs such as the brain, kidneys and eyes.

It is very common, especially in older adults, according to the NHS. The BHF says as many as 5 million adults in the UK have undiagnosed high blood pressure.

Readings are given as two numbers, for example 130/80. The NHS says you are usually considered to have high blood pressure if your reading is 140/90 or higher when checked by a healthcare professional, or 135/85 or higher when checked at home.

NICE CKS classifies hypertension into stages, using clinic readings first and then confirming with home or 24-hour monitoring.

Usually there are none. The NHS says high blood pressure does not usually cause symptoms, and the only way to find out if you have it is to have your blood pressure checked. The BHF says this is why regular checks matter.

Rarely, the NHS says it can cause headaches, blurred vision or chest pain. The BHF lists blurred vision, headaches and nosebleeds in rare cases.

The NHS says to get help from NHS 111 if you often have headaches or blurred vision, have chest pain that comes and goes, or have other symptoms you are worried could be caused by high blood pressure.

Call 999 if you have chest pain that does not go away, according to the NHS. It may be a heart attack.

• Sudden pain or discomfort in the chest that does not go away, which can feel like squeezing, pressure, burning or indigestion.

• Pain that spreads to the left or right arm, or the neck, jaw, stomach or back.

• Chest pain with feeling sweaty, sick, light headed or short of breath.

• The NHS says not to drive yourself to A&E.

• NICE CKS says people with a clinic reading of 180/120 or higher with signs of retinal bleeding or swelling of the optic nerve, or life-threatening symptoms such as new confusion, chest pain, signs of heart failure or acute kidney injury, need same-day specialist assessment.

A single high reading is not enough. The BHF says your blood pressure usually needs to be checked more than once, because it can go up and down a lot and can be higher in the clinic if you feel nervous or anxious.

The NHS says that if the test shows you might have high blood pressure, you may be asked to use a monitor at home for a few days, come back for another check in a few days or weeks, or wear a portable monitor that takes readings over 24 hours.

NICE CKS says diagnosis is then confirmed with ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM). While waiting, you should be offered tests for organ damage and for secondary causes, and an assessment of cardiovascular risk. The BHF says your GP may arrange blood tests for cholesterol and kidney function, or an ECG.

NICE CKS describes white-coat hypertension as blood pressure that is unusually raised during consultations but normal elsewhere.

The NHS says healthy lifestyle changes can help lower blood pressure, and that medicines can help you stay healthy. A GP will usually prescribe medicine if your blood pressure is very high, you are at higher risk of problems such as a heart attack or stroke, or it is still high after lifestyle changes.

The NHS says many different medicines exist, the choice depends on how high your blood pressure is, your age and your ethnicity, and most are tablets taken once a day. You may need more than one. The BHF lists beta blockers, diuretics, ACE inhibitors, angiotensin receptor blockers and calcium channel blockers as the usual types.

NICE CKS says management also includes lifestyle advice, considering a statin after cardiovascular risk assessment, monitoring response and an annual review. It gives target clinic readings below 140/90 for under 80s and below 150/90 for those aged 80 and over.

The NHS lists the following as things that can help lower blood pressure. The BHF adds oily fish, whole grains, fruit and vegetables, and limiting ultra-processed foods.

• Have a healthy, balanced diet.

• Exercise regularly: the NHS says to aim for at least 150 minutes of exercise a week.

• Lose weight if you are overweight.

• Do not eat too much salt. The NHS says adults should have no more than 6g of salt a day, around 1 level teaspoon, including salt in food and added in cooking and at the table.

• Do not drink too much alcohol: the NHS says to avoid regularly drinking more than 14 units a week.

• Do not drink too much caffeine, and do not smoke.

• Check food labels for salt, and look out for salt in dissolvable tablets such as some painkillers or vitamins, as the NHS notes.

NICE CKS says about 90% of people have primary hypertension, which has no identifiable cause, and about 10% have secondary hypertension with a known cause such as a kidney, hormonal or vascular disorder or the use of certain drugs.

The NHS lists factors that increase your chances: age, close relatives with high blood pressure, a Black African, Black Caribbean or South Asian ethnic background, an unhealthy diet high in salt, being overweight, smoking, drinking too much alcohol and long-term stress.

The BHF adds not getting enough exercise and carrying weight around the mid-section. It gives kidney disease, diabetes and obstructive sleep apnoea as secondary causes, and some medicines such as oral contraceptives and some over-the-counter or herbal remedies.

The BHF says around 1 in 10 women develop high blood pressure during pregnancy, often caused by pre-eclampsia, which increases the risk of long-term high blood pressure.

NICE CKS describes several kinds: chronic hypertension present before 20 weeks, gestational hypertension that starts after 20 weeks, and pre-eclampsia, which is new hypertension after 20 weeks with significant protein in the urine. Blood pressure and a urine test are done at each antenatal visit.

The NHS says early signs of pre-eclampsia are usually not noticed, which is why checks are routine. Other symptoms include a severe headache that does not go away with simple painkillers, vision problems, pain below the ribs, sudden swelling of the face, hands or feet, feeling very unwell, heartburn that does not go away and vomiting. If you are pregnant or have recently given birth and have these symptoms, the NHS says to get urgent help: call your maternity unit, or 111 if you cannot.

NICE CKS says women at high risk of pre-eclampsia are offered consultant-led care and aspirin 75 mg to 150 mg daily from 12 weeks until the birth, and that postpartum monitoring is essential.

The NHS says lowering your blood pressure even a small amount can help reduce the risk of heart disease, heart attacks, strokes, heart failure, kidney disease and vascular dementia. The BHF adds that untreated high blood pressure can cause loss of vision and sexual dysfunction.

If you have been diagnosed and it is under control, the BHF says you will normally be monitored yearly along with a review of your medicines, with more frequent checks when you start new medicines or change doses.

The NHS says you can get your blood pressure checked at a pharmacy or GP surgery, and that many pharmacies offer free checks for people aged 40 or over, with some pharmacies charging. The BHF says healthy adults aged 40 to 74 in England are likely to be invited for a free NHS Health Check every 5 years, which includes a blood pressure check.

Most diagnosis and treatment happens in primary care through your GP. Some people also use private health checks or buy a validated home monitor. Home monitoring can be useful for confirming a diagnosis, but a diagnosis and treatment plan should be agreed with a clinician.