High blood pressure (hypertension) is a common condition in which the force of your blood against your artery walls is too high, too often. Ongoing high blood pressure puts stress on your heart and can lead to health problems, such as heart disease and stroke.
At least 1 in 5 New Zealanders has high blood pressure, but most don't know they have it.
High blood pressure usually doesn't have symptoms, so the best way to find out if you have high blood pressure, is to get your blood pressure checked regularly. Your doctor, nurse or pharmacist can do this for you.
Untreated high blood pressure can cause serious problems such as stroke, heart attack and kidney failure.
You can manage high blood pressure through healthy lifestyle choices and medications if needed.
If you need medication, take it every day as prescribed. If you have any questions, ask your doctor or pharmacist.
What is high blood pressure?
Blood pressure (pēhanga toto) is the force of your blood pushing against the walls of your arteries. Read more about blood pressure.
Blood pressure is measured in millimetres of mercury (which is written as mmHg). Blood pressure readings are a combination of two measurements:
Systolic – the highest pressure against your arteries as your heart pumps. The normal systolic pressure is usually between 110–130 mmHg.
Diastolic – the pressure against your arteries as your heart relaxes and fills with blood. The normal diastolic pressure is usually between 70–80 mmHg.
High blood pressure may be considered to be 140/90 mmHg or higher. However, it is difficult to give an example of a high blood pressure reading, because it depends on the individual. The level of blood pressure that is high for you depends on lots of different factors and your overall risk of heart attack or stroke. Generally, the lower your blood pressure, the better. If you have a history of heart disease, diabetes or a high risk of heart attack or stroke, it's recommended you lower your blood pressure to less than 130/80. See Who needs to get their blood pressure checked?
A single high blood pressure reading does not necessarily mean that you have high blood pressure. It's normal for your blood pressure to rise and fall during the day, depending on what you have been doing (eg, exercise) and how you are feeling (eg, stressed).
You are usually considered to have high blood pressure if your blood pressure stays high for 3 separate readings, over at least 3 months. For some people, doing measurements at home with a machine can be more accurate than doing it in the clinic with your doctor or nurse.
To find out if you need to do something about your blood pressure levels, visit your doctor and have a heart and diabetes check. In your heart and diabetes check, your doctor, nurse or other health professional will discuss your ideal blood pressure, taking into account your overall risk of having a heart attack or stroke.
Why is high blood pressure a problem?
Over time, high blood pressure damages your blood vessels. It can lead to the following complications.
High blood pressure often runs in families. Sometimes kidney or glandular disease may be responsible. However, eating too much salt, drinking too much alcohol, being overweight and not moving around enough each day can also contribute to high blood pressure and heart disease.
The effects of high blood pressure on your blood vessels are worsened by:
high levels of saturated fat in your diet
high blood cholesterol.
Some medicines may cause raised blood pressure or make controlling it more difficult. These medicines include:
the combined contraceptive pill
non-steroidal anti-inflammatories (NSAIDs)
some nasal drops and sprays
some cough medicines, eye drops and appetite suppressants.
Check with your doctor or pharmacist for alternatives.
Who needs to get their blood pressure checked?
Every adult should have your blood pressure checked regularly. The age you are advised to start having heart and diabetes checks depends on your age, ethnicity and other risk factors.
Age to start having heart and diabetes checks
If you have no known risk factors
Men: 45 years Women: 55 years
If you are Māori, Pasifika or South Asian1
Men: 30 years Women: 40 years
If you have the following risk factors:
you have a family history of diabetes, high cholesterol, heart attack or stroke2
you have gestational diabetes (diabetes during pregnancy) or prediabetes
you are overweight3
you have kidney disease
you have high blood pressure or cholesterol
you have previously had a heart trouble or stroke
you have a heart condition such as atrial fibrillation.
Men: 35 years Women: 45 years
If you have diabetes (type 1 or 2)
As part of your yearly diabetes review
If you haveschizophrenia, major depressive disorder, bipolar disorder or other severe mental illness
South-Asian peoples: Indian, including Fijian Indian, Sri Lankan, Afghani, Bangladeshi, Nepalese, Pakistani, Tibetan
Family history: Parent, brother or sister
Overweight: BMI ≥ 30 or weight around your tummy (waist circumference ≥ 102 cm in men or ≥ 88 cm in women)
High blood pressure does not usually have any symptoms, so the only way to find out if you have it is to get your blood pressure checked by your doctor, nurse or pharmacist. They will often take several readings over weeks or months to see what the trend is.
Your doctor may suggest 24-hour blood pressure monitoring. This involves wearing a blood pressure unit for up to 24 hours to collect a series of blood pressure and heart-rate readings at different times of the day and night. Read more about 24-hour blood pressure monitoring Heart Foundation, NZ
How is high blood pressure treated?
Your doctor will work out your five-year risk of cardiovascular disease (eg, heart attack or stroke) to work out the likely benefits of blood pressure-lowering interventions.
If you have low risk, following the self-care steps listed below, such as stopping smoking, eating a balanced diet, less salt, less alcohol and becoming more physically active, may be enough. If your risk is higher, you are likely to need medication as well as following the self-care steps.
Self-care for high blood pressure
Stop smoking–quitting is the most important step to reduce your risk of heart attack and stroke.
Achieve and maintain a healthy body weight. The more overweight you are, the more strain you put on your heart and cardiovascular system. For some people, losing 5–10kg of excess weight is enough to get your blood pressure back to normal. Check with your doctor, nurse or pharmacist as to what is right for you.
Eat a balanced diet low in saturated fat with whole grains, 8 servings of coloured vegetables and fruit, and 2 to 3 servings of low-fat milk or milk products a day. Learn more about the DASH eating plan to lower high blood pressure.
Eat less salt – use herbs, spices, citrus and vinegar for flavouring and dressings, choose low-salt versions of packaged foods, avoid pickled food and salty or fatty takeaway foods. Read more about reducing salt intake
Be active every day. Find ways to put a little bit more activity in your day at every opportunity. Take the stairs at work. Park 5 minutes further away. Aim to get 30 to 60 minutes of moderate activity most days of the week. Walking, cycling and swimming are ideal. Find an activity you enjoy so you can keep it up. Find out more about getting active.
Avoid eating large quantities of liquorice – it contains a chemical that can raise blood pressure.
Medicines for high blood pressure
Medications can help control high blood pressure and reduce the damage from high blood pressure, but they do not cure it. Usually, medication will need to be taken for life, unless losing weight and the lifestyle changes are so successful that your blood pressure returns to normal levels without medication.
There a variety of medicines that can be used to lower blood pressure. Each of these groups of medicines works differently. Sometimes 2 or 3 medications are needed and it may take time to find the right combination and dosage. Tell your doctor or pharmacist about any side effects you may have and follow instructions carefully.
Examples of medicines to treat blood pressure include:
Dr Hari Talreja is a renal physician/hypertension specialist with advanced training from Canada and a master’s degree from Harvard University in the USA. He is one of the very few American Society of Hypertension-certified hypertension specialists in New Zealand. He is the clinical lead for transplantation, hypertension and clinical research at Counties Manukau Health. He also practices at Ormiston Specialists Centre, Flatbush and Gilgit Road Specialist Centre, Epsom.
Credits: Health Navigator Editorial Team . Reviewed By: Dr Hari Talreja, Specialist Renal and Hypertension Services, Auckland
Last reviewed: 08 Jan 2020
How can high blood pressure be prevented?
High blood pressure is one of the most common health problems as people get older. With a little effort, there is much you can do to reduce your risk of getting high blood pressure and the increased risk of stroke and heart disease that goes with that.
Keep to a healthy body weight
One of the key risk factors for high blood pressure is being overweight. Being overweight can make you 2 to 6 times more likely to develop high blood pressure than if you are in the normal weight range. Even small amounts of weight loss can make a big difference in helping to prevent and treat high blood pressure.
Be active regularly
People who are physically active have a lower risk of getting high blood pressure (20–50% lower) than people who are not active. Even light activities, if done daily, can help lower your risk. Add more activity to your day. Aim to get 30 to 60 minutes of physical activity most days of the week. Walking, cycling and swimming are ideal. Find an activity you enjoy so you can keep it up.
Look for opportunities to add a few minutes here and there – it all helps. Take the stairs whenever you can, park 5 minutes further from work, go for a walk at lunchtime or when you get home. Read more about getting active.
Eat a balanced diet
Your diet – what you eat and drink – has a real effect on your heart and blood pressure. The more healthy your eating habits are, the lower your blood pressure will be. A heart healthy diet is low in saturated fat, whole grains, 8 servings of coloured vegetables and fruit, and 2 to 3 servings of low-fat milk or milk products a day. Read more about healthy eating.
Eat less salt
Cutting back on salt also helps prevent your blood pressure from rising. Reduce your sodium intake to 2300mg of sodium a day (about 6g salt) or less. This includes sodium from processed food. Use herbs, spices, fruit and vinegar for flavouring and dressings. If you have pre-prepared foods, avoid pickled food and avoid salty or fatty takeaway foods. Read more about reducing your salt intake.
Being smokefree is one of the best things you can do to lower your risk of heart attack and stroke. While smoking does not directly affect your blood pressure, it will cause your arteries to narrow just as high blood pressure does. This puts you at much higher risk of heart disease and stroke.
So, if you smoke and have high blood pressure, your arteries will narrow much more quickly and your risk of a heart attack or stroke in the future is dramatically increased. Because of this, as well as for all the other effects it has on your health, it well worth giving up smoking. Read more about quitting smoking.
Stress can make blood pressure go up, and over time may contribute to the cause of high blood pressure. There are many steps you can take to reduce your stress. Read more about managing stress.
Avoid eating large quantities of liquorice
Liquorice contains a chemical that can raise blood pressure. Eating more than 57g of black liquorice a day for at least 2 weeks could lead to potentially serious health problems, such as an increase in blood pressure and an irregular heart rhythm (arrhythmia).
For most people, liquorice found in foods is safe to eat and safe when consumed in small amounts for short periods of time.
Medicines can help control high blood pressure and can reduce the damage from it, but do not cure high blood pressure. Usually medication will need to be taken for life, unless losing weight and the lifestyle changes are so successful that your blood pressure returns to normal levels without medication. Medicines that are used to control high blood pressure are called antihypertensives.
There are different groups or classes of medicines that can be used to lower blood pressure. Each of these groups work differently. Tell your doctor or pharmacist about any side effects you may have and follow instructions carefully.
Classes of blood pressure medicines
Angiotensin-converting enzyme (ACE) Inhibitors (also called ACE inhibitors)
ACE inhibitors block a hormone in the blood that causes blood vessels to tighten, and in this way relax the blood vessels and lower blood pressure. Examples include:
Angiotensin receptor blockers (also called ARBs)
These also control hormones that affect blood pressure. Examples include:
These medicines are often used to reduce blood pressure when other options are not suitable or working well enough. Examples include:
Calcium channel blockers
These medicines block calcium from getting into your cells and in this way relax the blood vessels and lower blood pressure. Examples include:
These medicines remove unwanted fluid from the body, which helps lower blood pressure. Examples include:
Choosing the right blood pressure medicines for you
Research shows that some types of blood pressure medicines work better in different types of people, and the choice of blood pressure medicines can depend on your:
medical problems (such as kidney disease or angina)
medical history, for example which blood pressure medicines you have tried in the past.
Since everyone is different, some medicines will work better for others than they do for you. Your doctor and nurse will usually go through a number of steps to find the right blood pressure medicines for you. Often two or three medications are needed and it may take time to find the right combination and dosage.
Medicines used to treat high blood pressure can cause side effects, although not everyone gets them. It is important to let your doctor or pharmacist know about any side effects you may have and to follow instructions carefully.
If treatment lowers your blood pressure too much, you may feel faint or dizzy, or notice excessive tiredness or heaviness in your legs. If you sit or lie down, these feelings will pass. Some medicines may make you feel faint if you get out of bed or stand up too quickly, suddenly exert yourself or get out of a hot shower or bath.
A cough, and erection problems in men are other possible side effects. Other medications can sometimes affect your blood pressure medication.
If you are prescribed new medications for other issues, remember to tell your doctor that you are taking blood pressure medication, and also any other medications you are taking. Your doctor needs this information to ensure the combination of medications is safe and effective.
If you are concerned about any side effects you are experiencing, talk to your doctor for further advice.
Tips on how to take your medicines effectively
Establish a routine; take your pills at the same time every day.
Do not keep your pills in the kitchen or bathroom: high temperatures or humidity can deteriorate them.
On long journeys, keep separately labelled supplies of your tablets in more than one bag.
All blood pressure drugs are dangerous to children and must be kept out of their reach.
If you have high blood pressure, it's important to get it checked regularly. Having poorly controlled blood pressure increases your chances of having a heart attack or stroke. There are a variety of blood pressure apps available but not all blood pressure apps are safe. Here is a blood pressure tracking app the Health Navigator team have reviewed.
Information for health professionals on hypertension
The information on this page will be of most interest to clinicians (doctors, nurses, specialists, etc.) and those seeking more detail.
Clinical guidelines for managing high blood pressure
Cardiovascular disease (CVD) risk assessment and management for people aged 30 to 74 years without prior CVD is based on 5-year CVD risk prediction equations from the New Zealand PREDICT study, the NZ Primary Prevention Equations. See heart risk assessment for clinicians for details.
Results of the SPRINT trial have found that in high-risk CVD patients (20% risk of an event in 10 years), a target BP of 120 mm Hg showed improved outcomes (reduced CVD events and death) as compared with a target BP of 140 mm Hg. Read more: Tight BP control improves CV outcomes in high-risk patients The British Hypertension Society (BHS) provides a list of blood pressure monitors they have validated. Wiysonge CS, Bradley HA, Volmink J, et al. Beta-blockers for hypertension. Cochrane Database Syst Rev. 2017 Jan 20;1:CD002003. doi: 10.1002/14651858.CD002003.pub5. (Review) [Cochrane Plain Language summary] Garjón J, Saiz LC, Azparren A, Elizondo JJ, Gaminde I, Ariz MJ, Erviti J. First-line combination therapy versus first-line monotherapy for primary hypertension. Cochrane Database of Systematic Reviews 2017, Issue 1. Art. No.: CD010316. DOI: 10.1002/14651858.CD010316.pub2. Conclusion: inconclusive, larger studies needed. [Cochrane Library] Cochrane hypertension library