High blood pressure (hypertension)
High blood pressure is when the force of your blood against your artery walls is too high, for too long. High blood pressure is diagnosed with a blood pressure check. Treating high blood pressure reduces your risk of heart disease, stroke, kidney failure and eye damage.
On this page
- How blood pressure is measured
- High blood pressure
- Risks of high blood pressure
- Causes of high blood pressure
- Diagnosing high blood pressure
- Measuring your blood pressure at home
- Treating high blood pressure
- Medicines for lowering blood pressure
- Check with your healthcare provider
- Self care for high blood pressure
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.
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 Foundationexternal 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.
Medicines for lowering blood pressure
If you are diagnosed with high blood pressure you may be prescribed 1 or more medicines to keep your blood pressure under control.
The various types of medicines work to lower blood pressure in different ways. Sometimes 2 or 3 medications are needed and it may take time to find the right combination and dosage.
These medicines can cause side effects, although not everyone gets them. Side effects can include feeling faint or dizzy.
These are the main types of blood pressure medicines.
ACE inhibitors block a hormone in your blood that causes your blood vessels to tighten. In this way, they relax your blood vessels and lower your blood pressure.
These also control hormones that affect your blood pressure.
These medicines are often used to reduce blood pressure when other options are not suitable or are not working well enough.
These medicines block calcium from getting into your cells and in this way relax your blood vessels and lower your blood pressure.
These remove unwanted fluid from your body, which helps lower your blood pressure.
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.
Self care for high blood pressure
There are many things you can do to lower your blood pressure. Even a small change can help and the more healthy choices you make, the better.
Smoking (Kaipaipa) causes damage throughout the body and is the biggest risk for heart disease, heart attack or stroke. Stopping smoking has benefits to almost every aspect of your health, including your heart, lungs, oral health, bones and skin.
There is strong evidence that drinking alcohol increases your risk of high blood pressure, a significant risk factor for heart disease.
If you currently do not drink any alcohol, then do not start drinking. If you do drink alcohol — it is better to drink less.
Too much salt in our diet can cause high blood pressure. Reducing the amount of salt we eat reduces our long term risk of heart disease.
Adults should not eat more than 5g of salt a day (about 1 teaspoon).
Three ways to eat less salt
- Eat more heart healthy foods.
- Swap to foods with lower salt
- Buy lower salt foods
Salt and your heart — Heart Foundationexternal link
Heart healthy foods include vegetables and fruit, some whole grains in place of refined grains, beans and pulses (legumes), nuts, seeds, and other sources of healthy fats such as oily fish.
Maintaining a healthy weight can reduce your risk of developing health problems such as heart disease, stroke, and high blood pressure. Making small changes to your diet and building more movement into your day can help you maintain a healthy weight.