High blood pressure (hypertension)
How blood pressure is measured
Your heart pumps blood around your body through blood vessels called arteries. With each heartbeat, the blood pushes against the artery walls. The strength of this pushing is your blood pressure.
Blood pressure is measured in millimetres of mercury (which is written as mmHg). Blood pressure readings are a combination of 2 measurements.
- The first (top) number is the pressure when your heart pumps (systolic pressure). The normal systolic pressure is usually between 110 and 130 mmHg.
- The second (bottom) number is the pressure when your heart relaxes (diastolic pressure). The normal diastolic pressure is usually between 70 and 80 mmHg.
For example your blood pressure may be 130 over 78 which would be written as 130/78.
High blood pressure
For most people the ideal blood pressure is 120/80.
Generally a high blood pressure is a reading of 140/90 mmHg or higher. However if you are other medical conditions such as diabetes, heart or kidney disease you will need to have lower blood pressure.
You are usually considered to have high blood pressure if your blood pressure stays high for 3 separate readings, over at least 3 months.
Risks of high blood pressure
Having high blood pressure increases your risk of:
- heart attack
- stroke
- heart failure
- kidney damage
- eye damage.
Causes of high blood pressure
There are many factors for having high blood pressure. Some factors include:
- getting older
- having a family member with high blood pressure
- smoking
- too much salt and processed food
- too much alcohol
- being overweight
- stress
- not being physically active.
High blood pressure is sometimes caused by an underlying health condition or taking a certain medicine.
Diagnosing high blood pressure
The only way of knowing whether you have high blood pressure is to have a blood pressure check. Every adult should get their blood pressure checked regularly as part of a heart and diabetes check.
Heart and diabetes checks - Heart Foundation (external link)
Your healthcare provider may want to take several blood pressure measurements on a few separate occasions. This is because your blood pressure normally changes throughout the day. It is lower when you are asleep or relaxing and goes up when you move around. It can also be increased by stress and stimulants like nicotine and caffeine.
They may also suggest you measure your blood pressure at home or have a 24 hour blood pressure monitor.
Measuring your blood pressure at home
Home blood pressure measurements can help:
- when your healthcare provider thinks you may have high blood pressure due to anxiety from being measured at their surgery
- when there is a big variation in your blood pressure measurements between visits
- to check whether your medication is working or if it is causing low blood pressure (hypotension)
- when you are not responding to blood pressure lowering treatments.
The Heart Foundation has information to help you measure your blood pressure at home and tips for buying a monitor.
Taking your blood pressure at home - Heart Foundation (external link)
Treating high blood pressure
You can improve your blood pressure and reduce the risk of complications by:
- following the self care guidelines
- taking blood pressure medicines if prescribed by your healthcare provider.
Check with your healthcare provider
Check with your healthcare provider or pharmacist before starting any other medicines or supplements as these can affect your blood pressure medicines.
This is especially important with anti-inflammatory pain relievers such as ibuprofen and diclofenac.