High blood pressure (hypertension)
Key facts
- High blood pressure, also known as hypertension, is a common condition that can cause health problems.
- High blood pressure does not usually cause any symptoms, so it's important to have regular blood pressure checks.
- You can reduce your chance of having high blood pressure by eating a healthy diet without too much salt, keeping active and limiting how much alcohol you drink.
- You can also help treat high blood pressure with lifestyle measures.
- Some people with high blood pressure need to take medicines to keep their blood pressure at healthy levels.
What is high blood pressure?
High blood pressure, also known as hypertension, is a common condition. It usually does not cause any symptoms, but it increases your risk of other health problems.
About 1 in every 3 Australian adults has high blood pressure.
Blood pressure is the 'force' that keeps blood moving through your arteries (blood vessels) after it leaves your heart. Blood pressure is measured in millimetres of mercury (written as mmHg).
An example of a blood pressure reading is '120 over 80'. This is written as 120/80mmHg. The 2 numbers refer to:
- Systolic blood pressure is the pressure as your heart pumps blood through your arteries — the top number.
- Diastolic blood pressure is the pressure in your arteries when the heart relaxes between beats — the bottom number.
Your blood pressure varies, depending on your general health and activity levels.
Blood pressure is considered high if your readings are consistently more than 140/90mmHg. This is true whether:
- your systolic pressure is 140 or higher
- your diastolic pressure is 90 or higher
- both measurements are high
What are the symptoms of high blood pressure?
Most people with high blood pressure have no symptoms. This is why it's important to have your blood pressure checked regularly.
Symptoms of very high blood pressure can include:
- headaches
- dizziness
- nosebleeds
- problems with your eyesight
Very high blood pressure can also cause complications, such as heart attack or stroke.
What causes high blood pressure?
For most people, the cause of high blood pressure is not known. This type of high blood pressure is sometimes called 'essential hypertension'.
Your risk of having high blood pressure can be increased if you:
- leading a sedentary lifestyle (do little or no exercise)
- are overweight or obese
- eat a diet with high salt levels
- drink more alcohol than is recommended
In a few people, there is a known cause for high blood pressure, such as:
- narrowing of the arteries to your kidneys
- kidney disease
- some hormonal conditions
- some medicines or drugs
- sleep apnoea
- complications of pregnancy
Some people have 'white-coat hypertension'. This is where your blood pressure rises in your doctor's surgery, but is lower when measured elsewhere.
When should I see my doctor?
If you're over 18 years, you should have your blood pressure checked by your doctor at least every 2 years. This is because most people with high blood pressure do not have any symptoms.
Sometimes people develop very high blood pressure quickly. If this happens, there is a risk of serious complications and you will need urgent hospital treatment.
Symptoms of very high blood pressure can include:
- headaches — which may be felt at the back of your head
- vomiting
- problems with your eyesight
- confusion
- seizures
- chest pain
- shortness of breath
If you have any of these symptoms, go to your nearest hospital emergency department or call triple zero (000) for an ambulance.
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How is high blood pressure diagnosed?
Your doctor will ask about any symptoms you have. They will also want to know about your:
- family medical history
- overall health
- lifestyle
- medicines
Your doctor may do an overall physical examination. They can measure your blood pressure in the clinic. If your blood pressure is high (140/90mmHg or higher), your doctor may ask you to:
- check your blood pressure at home
- wear a blood pressure monitor over a 24-hour period
This will help you and your doctor to see how your blood pressure varies through a regular day. It helps to make sure you get an accurate diagnosis.
Your doctor may also recommend some tests, including:
- blood tests
- an electrocardiogram (ECG)
- a kidney ultrasound
Some people may be referred to a specialist doctor for treatment, such as a cardiologist (heart specialist) or kidney specialist.
You may be referred to a dietitian or exercise physiologist to help with lifestyle changes.
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How is high blood pressure treated?
Treatment aims to lower your blood pressure and reduce your risk of cardiovascular disease.
Lifestyle measures
Mild high blood pressure can often be treated by making lifestyle changes, including:
- doing regular physical activity
- stopping smoking
- eating a healthy diet and reducing your salt intake
- losing weight if you are overweight
- limiting your alcohol intake to no more than 2 standard drinks per day for males, or 1 standard drink per day for females
Medicines for high blood pressure
In some people, lifestyle changes may not be enough. You may also need medicines to help reduce your blood pressure levels to within the normal range.
Some people will need more than one type of medicine to control their blood pressure. You should regularly review any medicines you are taking for high blood pressure with your doctor or specialist.
What are the complications of high blood pressure?
There are many complications of ongoing high blood pressure. These include:
- heart disease and heart attacks
- stroke
- heart failure
- eye conditions that can affect your sight
- chronic kidney disease
Treating high blood pressure helps prevent complications.
Can high blood pressure be prevented?
Having a healthy lifestyle helps reduce your chances of getting high blood pressure. You can have a healthy lifestyle by:
- following a healthy diet
- getting regular physical activity
- not smoking or vaping
- limiting how much alcohol you drink
Resources and support
The Heart Foundation provides information and support for people with high blood pressure. There is information in languages other than English.
The Stroke Foundation has more information about blood pressure and stroke.
Dietitians Australia has a fact sheet about salt, which includes ways to reduce salt intake and when to see a dietitian.
Aboriginal and/or Torres Strait Islander people
NACCHO, the Heart Foundation and NPS MedicineWise have information on high blood pressure for Aboriginal and/or Torres Strait Islander people.
You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: November 2024
