Whats the bottom number of blood pressure mean

High blood pressure, or hypertension, rarely has noticeable symptoms. But if untreated, it increases your risk of serious problems such as heart attacks and strokes.

Around a third of adults in the UK have high blood pressure, although many will not realise it.

The only way to find out if your blood pressure is high is to have your blood pressure checked.

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 from 140/90mmHg (or an average of 135/85mmHg at home) – or 150/90mmHg (or an average of 145/85mmHg at home) if you're over the age of 80
• ideal blood pressure is usually considered to be between 90/60mmHg and 120/80mmHg, while the target for over-80s is below 150/90mmHg (or 145/85mmHg at home)

Blood pressure readings between 120/80mmHg and 140/90mmHg could mean you're at risk of developing high blood pressure if you do not take steps to keep your blood pressure under control.

Everyone's blood pressure will be slightly different. What's considered low or high for you may be normal for someone else.

Risks of high blood pressure

If your blood pressure is too high, it puts extra strain on your blood vessels, heart and other organs, such as the brain, kidneys and eyes.

Persistent high blood pressure can increase your risk of a number of serious and potentially life-threatening health conditions, such as:

• heart disease
• heart attacks
• strokes
• heart failure
• peripheral arterial disease
• aortic aneurysms
• kidney disease
• vascular dementia

If you have high blood pressure, reducing it even a small amount can help lower your risk of these health conditions.

Check your blood pressure

The only way of knowing whether you have high blood pressure is to have a blood pressure test.

All adults over 40 are advised to have their blood pressure checked at least every 5 years. 

Getting this done is easy and could save your life.

You can get your blood pressure tested at a number of places, including:

• at your GP surgery
• at some pharmacies
• as part of your NHS Health Check
• in some workplaces

You can also check your blood pressure yourself with a home blood pressure monitor.

Find out more about getting a blood pressure test

Things that can increase your risk of getting high blood pressure

It's not always clear what causes high blood pressure, but there are things that can increase your risk.

You might be more at risk if you:

• are overweight
• eat too much salt and do not eat enough fruit and vegetables
• do not do enough exercise
• drink too much alcohol or coffee (or other caffeine-based drinks)
• smoke
• do not get much sleep or have disturbed sleep
• are over 65
• have a relative with high blood pressure
• are of black African or black Caribbean descent
• live in a deprived area

Making healthy lifestyle changes can sometimes help reduce your chances of getting high blood pressure and help lower your blood pressure if it's already high.

Treatment for high blood pressure

Doctors can help you keep your blood pressure to a safe level using:

• lifestyle changes
• medicines

What works best is different for each person.

Talk to your doctor to help you decide about treatment.

This patient decision aid (PDF, 132kb) can also help you to understand your treatment options.

Lifestyle changes to reduce blood pressure

These lifestyle changes can help prevent and lower high blood pressure:

• reduce the amount of salt you eat and have a generally healthy diet
• cut back on alcohol 
• lose weight if you're overweight
• exercise regularly
• cut down on caffeine
• stop smoking

Some people with high blood pressure may also need to take 1 or more medicines to stop their blood pressure getting too high.

Medicines for high blood pressure

If you're diagnosed with high blood pressure, your doctor may recommend taking 1 or more medicines to keep it under control.

These come as tablets and usually need to be taken once a day.

Common blood pressure medicines include:

• ACE inhibitors – such as enalapril, lisinopril, perindopril and ramipril
• angiotensin-2 receptor blockers (ARBs) – such as candesartan, irbesartan, losartan, valsartan and olmesartan
• calcium channel blockers – such as amlodipine, felodipine and nifedipine or diltiazem and verapamil
• diuretics – such as indapamide and bendroflumethiazide
• beta blockers – such as atenolol and bisoprolol
• alpha blockers – such as doxazosin
• other diuretics – such as amiloride and spironolactone

The medicine recommended for you will depend on things like how high your blood pressure is, your age and your ethnicity.