One in three Australians have high blood pressure. Here’s how to reduce it

One in three Australians have high blood pressure. Here’s how to reduce it

One in three Australians – or around 6.8 million people – have high blood pressure, according to the Heart Foundation.

High blood pressure “is a smouldering public health crisis,” says Dr Rishi Wadhera, an associate professor of medicine at Harvard Medical School and an author of new research showing that blood pressure screenings have not returned to what they were before the COVID-19 pandemic.

High blood pressure can raise the risk of heart attack, stroke, pregnancy complications and other health problems, but the symptoms are “often silent,” Wadhera says. “I worry it flies under the radar for many patients.”

Here’s what to know about the issue, and how to get your blood pressure under control.

What is blood pressure? And what's a normal level?

Blood pressure is the force that blood exerts against artery walls in the heart, says Dr Jim Liu, a cardiologist at the Ohio State University Wexner Medical Centre. You’ll always hear your blood pressure given as two numbers: the top number, known as systolic pressure, measures that force when the heart contracts. The bottom number, known as diastolic pressure, gauges the force when the heart muscle relaxes. It’s measured in units known as millimetres of mercury, or mm Hg.

You can have your blood pressure checked during a medical appointment or at a pharmacy, or you can check it yourself with a home monitor. The Heart Foundation defines normal blood pressure as below 120/80 mm Hg.

Very high blood pressure can cause symptoms including severe headaches, chest pain and dizziness. For many people, however, blood pressure increases too gradually for them to notice these issues, Liu says.

Why is high blood pressure harmful?

High blood pressure forces the heart to work harder to pump blood. Over time, the overwhelmed heart can slowly start to falter and struggle to pump blood out to the rest of the body, a condition called heart failure.

The force and friction of high blood pressure can also injure the delicate lining of the arteries, Liu says. Tears in the artery wall allow LDL cholesterol – also known as the “bad” cholesterol – to latch on and form clumps, or plaques, in these gaps. This can block blood flow and, in some patients, cause a heart attack.

Blockages in arteries that carry blood to the brain can lead to a stroke. Long-term damage to blood vessels in the brain can also lead to a condition called vascular dementia, Liu says.

What leads to hogh blood pressure?

All arteries stiffen over time, leading blood pressure to climb steadily as people age.

Multiple risk factors have been linked to high blood pressure, including smoking, heavy drinking, obesity and chronic stress. A lack of exercise and diets high in sodium and processed foods have also been associated with an increased risk of hypertension.

How can you reduce your blood pressure?

For some people, lifestyle changes can be as powerful as medication, says Dr Martha Gulati, director of preventive cardiology at the Smidt Heart Institute at Cedars-Sinai in Los Angeles. She recommends at least 30 minutes of moderate exercise a day and sleeping seven to nine hours a night, both of which are associated with lower blood pressure. Maintaining or achieving a healthy body weight can also reduce blood pressure, Gulati says.

Avoiding products that contain nicotine is important. Using nicotine drives up blood pressure, narrows blood vessels and may contribute to hardening of arteries.

Some research suggests that following a low-sodium diet could reduce blood pressure by 2 to 8 mm Hg for some patients, and that adopting the DASH diet – which emphasises fruits, vegetables and low-fat dairy products – could reduce blood pressure by 8 to 14 points. Abstaining from alcohol or limiting consumption to no more than one glass per day for women and two glasses for men could reduce blood pressure by 2 to 4 points.

People who can’t lower their blood pressure to normal levels through lifestyle changes will need medication, Gulati says. Water pills, or diuretics, help remove sodium and water from the body, bringing down blood pressure. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) both relax blood vessels, though they work in different ways. Calcium channel blockers help relax the muscle cells of blood vessels, and some slow your heart rate. People who can’t lower their blood pressure with these drugs may need additional medications. Doctors take a patient’s age, health and risk factors into consideration before deciding what medication to prescribe.

“Blood pressure is the most modifiable risk factor for heart disease and stroke,” Gulati says. “With lifestyle changes and medications, our patients can take control of it – and their heart health.”

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