Overview - High blood pressure (hypertension)

High blood pressure (hypertension) increases your risk of developing health conditions such as:

  • heart disease
  • atrial fibrillation
  • stroke
  • dementia
  • loss of eyesight
  • kidney failure

Your heart pumps blood down the blood vessels to the body's organs, for example your brain, eyes and kidneys. The higher the pressure in your system, the more strain is placed on your heart and your organs.

High blood pressure does not usually have any symptoms. The only way to find out if you have it is to get your blood pressure checked.

If you are 40 years or older, have your blood pressure checked at least once a year.

Have your blood pressure checked at least once every 5 years if you’re 18 to 39 years and you're healthy with no family history of high blood pressure.

Causes of high blood pressure

In most cases, it's not clear exactly what causes 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
  • a high amount of salt in your food
  • lack of exercise
  • being overweight
  • regularly drinking large amounts of alcohol
  • eating a lot of liquorice
  • smoking
  • long-term sleep deprivation or obstructive sleep apnoea

In about 1 in 20 cases, high blood pressure happens as the result of an underlying health condition or taking a certain medicine.

Preventing and reducing high blood pressure

There are changes you can make to your lifestyle to prevent and reduce high blood pressure.

Some of these will lower your blood pressure in a matter of weeks, while others may take longer.

Try to:

  • cut your salt intake to less than 6g (0.2oz) a day (about 1 teaspoonful)
  • eat a low-fat, balanced diet - include plenty of fresh fruit and vegetables
  • be active
  • cut down on alcohol
  • lose weight – find out what your ideal weight is using the BMI healthy weight calculator
  • drink less caffeine – found in coffee, tea and cola
  • stop smoking
  • get at least 6 hours of sleep a night

You can make these changes straight away, even if you're already taking blood pressure medicines.

Make these changes early on and you may be able to avoid needing medicines.

High blood pressure in pregnancy

You and your baby will need to be more closely monitored during pregnancy if you have high blood pressure.

There are 2 types of high blood pressure that can develop during pregnancy:

Most women with pre-eclampsia go on to have healthy babies. If untreated, pre-eclampsia can be dangerous and even fatal for you and your baby. Check the signs for pre-eclampsia.

If you had high blood pressure before you were pregnant, you have chronic hypertension.

Talk to your GP or a pharmacist if you have high blood pressure and you’re planning a pregnancy or you think you may be pregnant.

Where to get your blood pressure checked

You can ask for a blood pressure check – you don't have to wait to be offered one.

You can get your blood pressure checked:

  • at your GP surgery by a GP, practice nurse, healthcare assistant or through a self-service machine
  • at some pharmacies
  • in some workplaces
  • at a health event

You can also test your blood pressure at home using a home testing kit.

Having a blood pressure test

An automatic device with sensors and digital displays are used to check blood pressure.

You can usually find out your result straight away from the healthcare professional or on the digital display.

Having a raised blood pressure reading in one test does not mean you have high blood pressure.

Blood pressure can fluctuate throughout the day. Feeling anxious or stressed when you visit your GP can also raise your blood pressure.

If you have a high reading, you may be asked to take some readings with a home blood pressure monitor. You may have to wear a 24-hour monitor that checks your blood pressure throughout the day.

Home blood pressure testing

You can do blood pressure tests at home using your own blood pressure monitor.

Measure your blood pressure twice a day. It's best to do it in the morning and the evening, while you're sitting down.

Each time take 2 readings, 1 minute apart. Continue to measure your blood pressure twice a day for 7 days.

Your GP or nurse will use this information to work out your average blood pressure.

This can give a more accurate measure of your blood pressure. It can also make it easier to monitor your condition over time.

Slaintecare logo
This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

Page last reviewed: 3 January 2022
Next review due: 3 January 2025