As blood is pumped by the heart around the body, the pressure with which it pushes against the walls of blood vessels changes.
When the heart is relaxed, the pressure is lower.
Your blood pressure is a measurement taken of the highest reading and the lowest reading.
It is given as two figures – highest over lowest.
What is high blood pressure?
Your blood pressure is high if the reading is higher than 140/90.
That is, you have high blood pressure if the higher figure is higher than 140, or the lower figure is higher than 90, or both.
This is also known as hypertension. About 30% of Australians over the age of 25 have high blood pressure.
About 30% of Australians over the age of 25 have high blood pressure.
Why is your blood pressure important?
Your blood pressure is important because if it is too high, it affects the blood flow to your organs. Over the years, this increases your chances of developing heart disease, stroke, kidney failure, diabetes, eye disease, erectile dysfunction and other conditions.
The Royal Australian College of General Practitioners (RACGP) recommends that if you are concerned about cardiovascular disease but have no symptoms, talk to your doctor or specialist about whether the benefits will outweigh the risks involved with specific testing for heart disease or stroke.
For further information, visit the Choosing Wisely Australia website.
If you’re over 18, you should have your blood pressure checked by your doctor at least every two years, or more often if advised.
What causes high blood pressure?
For most people, the cause of high blood pressure is not known. This is known as ‘essential’ or ‘primary’ hypertension.
But while the cause is not known, it is clear that various conditions and behaviours make high blood pressure more likely. These are known as risk factors, and include:
- leading a sedentary lifestyle (with little or no exercise)
- being overweight
- a diet with a high salt intake
- high blood cholesterol
- a family history of high blood pressure
- high alcohol consumption.
In a few people, there is an identifiable cause such as narrowing of the arteries of the kidney (renal stenosis) or some hormonal conditions.
What are the symptoms of high blood pressure?
Most people with high blood pressure have no symptoms, and may feel quite well. This is why it’s important to see your doctor and have your blood pressure checked regularly, especially if you have one or more of the risk factors listed above.
Check your symptoms with healthdirect’s Symptom Checker to get advice on when to seek medical attention.
Diagnosing high blood pressure
Your blood pressure varies from day to day, even moment to moment. Generally, if a person has a blood pressure reading greater than 140/90 taken on three different occasions, they have high blood pressure.
What is the treatment for high blood pressure?
For most people, the first step is to make changes to their lifestyle. These include:
- doing regular physical activity
- stopping smoking
- improving your diet to reduce salt, reduce fat and eat plenty of fruit and vegetables
- losing weight
- limiting your alcohol intake to no more than two drinks per day for men, or one drink per day for women with high blood pressure.
Lifestyle changes may not be enough. Some people also need medication to help reduce blood pressure levels to normal. While medicines are usually very effective at lowing blood pressure, they may cause side effects in some people.
Usually doctors will start a person on a low dose of a medicine and see how it goes. If it doesn’t work well enough, or if there are troublesome side effects, other medicines will be used, sometimes in combination, until the blood pressure is controlled. This can take time. Some people will take medicines for life, although others will find that continuing to lose weight and change their diet reduces the need for medicines.
Someone with high blood pressure that is very high, or is causing symptoms such as headache, or if they have conditions such as heart disease or diabetes, may need urgent treatment with medicines to bring the blood pressure down to normal levels.
RACGP recommends that you regularly review with your doctor or specialist any medications you are taking for high blood pressure or high cholesterol to assess the ongoing benefits and risks. For further information, visit the Choosing Wisely Australia website.
Preventing high blood pressure
If you can follow a healthy diet, keep to a healthy weight and avoid smoking, you will reduce your chances of having high blood pressure.
There are a number of resources and services available if you need help or more information on high blood pressure:
- Healthdirect - Is your blood pressure healthy?
- Download Managing high blood pressure information sheet from the Heart Foundation
- High Blood Pressure Research Council of Australia
- National Stroke Foundation High Blood Pressure and Stroke
Sources: Heart Foundation (High blood pressure), High Blood Pressure Research Council of Australia (High blood pressure), Mayo clinic (low blood pressure (hypotension)), myDr (How high blood pressure should be treated), The Royal Australian College of General Practitioners (Guidelines for preventive activities in general practice (Blood pressure)), myvmc (High blood pressure).
Choosing Wisely Australia (Choosing Wisely recommendations)
Last reviewed: April 2014