High Blood Pressure

UK practice separates clinic readings (taken by a health professional) from home or ambulatory averages. People are often more tense in a clinic, so the same person typically records slightly lower numbers at home. The thresholds are set accordingly.^{[14]NICE NG136}

High blood pressure is generally considered to be a clinic reading of 140/90 mmHg or higher confirmed by a home or ambulatory average of 135/85 mmHg or higher. Only one of the two numbers needs to be raised for the reading to count as high.

• Blood pressure varies naturally from minute to minute and hour to hour.
• "White coat" effect — some people read consistently higher in a clinic than they do in everyday life. This is common and is not the person being dramatic.
• Masked hypertension works the other way: normal in clinic, raised at home. This is one reason home readings are useful.
• A wrong cuff size, talking during the reading, a full bladder, crossed legs or an unsupported arm can all push a reading up noticeably.
• So a single high number is a prompt to check properly, not a diagnosis and not usually an emergency on its own.
• NICE recommends confirming suspected hypertension with ambulatory monitoring, or home monitoring if ambulatory monitoring is unsuitable or declined.^{[14]NICE NG136}

High blood pressure is often called a silent condition because it rarely causes anything you can feel. You cannot judge your blood pressure by how well you feel, and headaches, tiredness or a flushed face are not reliable signs of it.^[1]NHS

• Most people with high blood pressure feel completely well.
• Very high blood pressure can occasionally cause headaches, blurred vision, nosebleeds, chest pain or breathlessness — but these symptoms have many other causes too.
• Feeling fine is not a reason to skip checks, and feeling unwell is not proof that your blood pressure is the cause.
• This is why routine checks matter: they find a problem long before it does harm.^{[9]NHS Health Check}

• Adults should have their blood pressure checked at least every five years, and more often if it has been borderline before.^{[4]NHS — blood pressure test}
• In England, adults aged 40 to 74 without certain existing conditions are invited for an NHS Health Check every five years, which includes blood pressure.^{[9]NHS Health Check}
• Many community pharmacies offer free blood pressure checks to adults aged 40 and over, with no appointment and no referral needed.^{[10]NHS pharmacy services}
• Ask sooner if you have diabetes, kidney disease, heart disease, a family history of high blood pressure or early stroke, or if you are of Black African or African-Caribbean family origin, where high blood pressure is more common.
• Ask sooner if you are pregnant or planning pregnancy, or if you are taking a medicine that can raise blood pressure.

For most people no single cause is found. This is called primary or essential hypertension and it builds slowly with age as arteries stiffen. A smaller group has a specific underlying cause, known as secondary hypertension.^{[2]NHS — causes}

• Getting older — very common, and not a sign you have done anything wrong.
• A close family history of high blood pressure.
• Being of Black African or African-Caribbean family origin.
• Carrying extra weight, particularly around the middle.
• A diet high in salt, and one low in fruit and vegetables.
• Regularly drinking more alcohol than the UK guideline of 14 units a week.
• Smoking, and long-term stress, poor sleep or untreated sleep apnoea.
• Low physical activity, and long periods of sitting.
• Kidney disease, diabetes, thyroid problems and some hormone conditions.
• Some medicines and substances, including certain contraceptive pills, steroids, some antidepressants, regular anti-inflammatory painkillers, decongestants, herbal remedies such as liquorice, and cocaine or other stimulants. Never stop a prescribed medicine on your own — ask for a review.

Lifestyle changes can make a real difference, and they work alongside medicines rather than instead of them. No single change guarantees a particular drop, and blood pressure is not simply a matter of willpower — age, genetics and other conditions all play a part.^{[3]NHS — treatment}

• Salt — UK adults are advised to have no more than 6g a day, about a teaspoon. Most of it comes from bread, sauces, processed meat and ready meals rather than the salt cellar.^{[18]NHS — salt in your diet}
• Food — more vegetables, fruit, beans, wholegrains and unsalted nuts; less processed meat and fewer ready meals. Some people are advised to be careful with potassium-rich salt substitutes, particularly with kidney disease or certain medicines, so check first.
• Movement — aim towards 150 minutes of moderate activity a week, built up gradually. Walking, cycling, swimming and gardening all count.
• Weight — if you are carrying extra weight, even a modest loss can lower blood pressure. Small, sustainable changes beat crash diets.
• Alcohol — keeping within 14 units a week, spread over three or more days, helps. Cutting back from heavy drinking often lowers readings noticeably.
• Smoking — stopping does not lower resting blood pressure much on its own, but it sharply reduces the risk of stroke and heart attack. Free NHS stop-smoking support is available.
• Caffeine — very high intakes can push readings up. There is no need to give up tea or coffee entirely for most people.
• Sleep and stress — poor sleep, shift work and untreated sleep apnoea are all linked to higher blood pressure. Loud snoring with pauses in breathing is worth mentioning to your GP.

• Kidneys — high blood pressure damages the small vessels in the kidneys, and kidney disease in turn pushes blood pressure up. Each makes the other worse, so both are treated together.
• Diabetes — high blood pressure is common alongside diabetes, and controlling both lowers the risk of eye, kidney, nerve and heart complications.
• Stroke — high blood pressure is the single biggest treatable risk factor for stroke, both the clot type and the bleeding type.^{[7]NHS — stroke}
• Heart — sustained high pressure thickens the heart muscle and contributes to angina, heart attack, atrial fibrillation and heart failure.
• Eyes and brain — the small vessels in the retina and brain are also affected, which is why high blood pressure is linked to vision damage and to vascular dementia.
• Treatment is not just about the number. It is about lowering all of these risks together, which is why cholesterol, smoking and diabetes are usually addressed at the same time.^{[16]NICE NG238}

• Most people with high blood pressure work normally. If side effects such as tiredness or dizziness are a problem, ask about a medicine review before assuming you must simply cope.
• Reasonable adjustments — flexible hours, rest breaks, help with shift patterns — can be discussed with an employer or occupational health.
• Driving: car and motorcycle drivers usually do not need to tell the DVLA about high blood pressure alone, but you must not drive if symptoms such as dizziness affect your driving. Stricter rules apply to bus, coach and lorry licences. Always check the current GOV.UK guidance for your circumstances.^{[17]GOV.UK — health conditions and driving}
• Travel: carry medicines in hand luggage with a copy of your prescription list, take more than you need, and declare the condition to your travel insurer. Hot weather and dehydration can lower blood pressure and cause dizziness.
• Keep an up-to-date medicine list on your phone or in your wallet.
• If cost is a barrier — prescriptions, heating, food or transport to appointments — there is practical help available and it is worth asking.

• Being told you have high blood pressure can be unsettling, particularly if a relative had a stroke or heart attack.
• Some people become very anxious about home readings and check repeatedly. That usually raises the numbers and the worry. Agree a checking routine with your practice and stick to it.
• Low mood, stress and poor sleep affect both blood pressure and the energy to manage it.
• Carers and relatives often do the remembering, the prescriptions and the lifts to appointments. That deserves support too.
• If you are struggling to keep yourself safe, get help now through our crisis page or by calling 999 in an emergency.

Across the UK: NHS 111 online covers England. Elsewhere, start here:

In a life-threatening emergency, always call 999.