Do you know what your blood pressure is? For a surprisingly large number of people, the answer to that question is likely to be no. About 350,000 New Zealanders aren’t aware they have high blood pressure – also known as hypertension – and that it could be harming their health.
“It’s the number one risk factor for preventable deaths,” says cardiologist Gerry Devlin, medical director of the Heart Foundation. “The problem with high blood pressure is we don’t have symptoms until there are complications from it. Those can include heart attack, stroke, kidney failure and aortic dissection [a tear in the main artery]. So it’s really important we get better at diagnosing and managing it.”
Blood pressure is the force of the blood pushing against the walls of the arteries as the heart pumps it around the body. This changes throughout the day. It is lower when you are relaxing but tends to be higher in the morning as levels of the hormone cortisol rise. Exercise causes a temporary increase, as does stress. Even having a full bladder can elevate it slightly.
It’s looking at what blood pressure is like over a sustained period that is really important,” says Devlin. “If it is high then the heart has to work harder to push blood around. You can get changes in the walls of the arteries from the elevated pressure, which leads to plaque build-up. It increases the risk of atrial fibrillation, which can lead to heart failure and stroke, and it can damage blood vessels in the brain.”
The foundation is running an awareness campaign this month encouraging New Zealanders to get blood pressure checked, know their numbers and make changes if needed.
For most people, an optimal blood pressure is 120/80, while 140/90 and above is considered high. The top number is the pressure when the heart beats (systolic) and the bottom number is the pressure when the heart relaxes (diastolic).
As we age, our arteries harden. Blood pressure tends to be higher and targets to improve it become more conservative, as it’s important to avoid lowering it too much and risking dizziness or falls. But for all of us, a healthy blood pressure lifestyle includes all the usual things: stay physically active, avoid being overweight, eat well, don’t smoke, limit alcohol, reduce salt consumption, sleep properly and manage stress.
Meditation has been shown to be an effective way to improve blood pressure, at least in the short term. Research published in BMJ Medicine found most relaxation techniques, including breath work, mindfulness, tai chi and progressive muscle relaxation, lowers both systolic and diastolic blood pressure for people with hypertension.
Increasing your potassium intake can also help. As well as foods rich in this essential nutrient – bananas, leafy greens, potatoes with skin, pulses – there are potassium-enriched, low-sodium salts available for cooking and seasoning.
For some people, lifestyle measures won’t be enough. “A lot of us will still need medication,” says Devlin. “As I say to my patients, that’s not admitting defeat. I’m on medications myself because high blood pressure runs in my family.”
In Australia, a National Hypertension Taskforce is aiming to improve the nation’s blood-pressure control. The goal is to move from having only 32% of people measuring less than 140/90 to 70%. Devlin says even if we could manage that in 50% of New Zealanders, it would save around 12,000 lives.
“For every 10-point drop in your systolic blood pressure you reduce your risk of a heart event by 20%,” he says.
Blood pressure checks can be done by GPs, nurse practitioners and some pharmacies. The Heart Foundation will be offering free checks at pop-up clinics throughout May.
Home monitors are another helpful way to keep track. The advice is to use them at the same time each day, in a quiet period when you are relaxed, and to take several readings.
“We want people to be aware of what the numbers mean for them, to have that conversation with their health practitioner and to follow up if it’s elevated,” says Devlin. “This is about wellness management, preventing getting sick in the years to come. We shouldn’t put our heads in the sand, because the consequences of getting it wrong are devastating.”
