Blood pressure checks

How blood pressure works, and what the normal ranges are.

Helen Foster
January 2018

High blood pressure puts strain on your heart and is a risk factor for a number of diseases, including heart attack and stroke. It’s also one of the most common health conditions affecting the heart and blood vessels, reports The Heart Foundation. As there are no obvious symptoms of high blood pressure, it’s important to get tested regularly from the age of 45 (35 if you’re Aboriginal or Torres Strait Islander).

A blood pressure test measures 2 things:        

• systolic pressure (the top number), the pressure when your heart pumps blood around your body
• diastolic pressure (the bottom number), the pressure in your heart when it relaxes between beats. 
  

What’s normal blood pressure?

Low blood pressure (or hypotension) is under 90/60. This isn’t always a problem but can sometimes include symptoms like dizziness, blurry vision, clammy skin, fatigue and fainting. For some, for example very fit people, low blood pressure is a sign of good health, reports Healthdirect. It’s riskier for older people who may be ill or at risk of a fall. If you have symptoms of low blood pressure, see your GP.

Normal blood pressure is 90/60 to 120/80.

The high end of normal is between 120/80 and 139/89. Your doctor might advise lifestyle changes, like doing more exercise, eating healthily, losing weight and cutting back on alcohol if appropriate.

High blood pressure (or hypertension) is more than 140/90. If you have hypertension, you may be encouraged to make the lifestyle changes above and be prescribed medication.

In some cases, measurements may not follow these exact numbers – particularly in older people, as systolic pressure rises with age. “But if either measure is higher than it should be the person has hypertension”, explains the Heart Foundation’s chief medical advisor, cardiologist Professor Garry Jennings.

How do you get your blood pressure checked?

HCF members aged over 18 with extras cover can get their blood pressure checked as part of a broader heart health check at selected HCF branches.

You can also get your blood pressure checked anytime you see a nurse or doctor. Some people have higher blood pressure at the GP simply because they’re nervous about seeing the doctor, this is sometimes referred to as ‘white coat syndrome’.

A study from University College London investigated ambulatory blood pressure readings – where people wear a cuff for 24 hours which sends readings back to their GP. It found ambulatory reading gives a more accurate blood pressure and is 50% more accurate than the traditional way at identifying those at most risk of death from heart disease.

With ambulatory readings “it’s possible to see the variation in a patient’s blood pressure during the day and at night. It’s measured during daily activities and away from the medical environment, which can alter how people respond,” explains Prof Jennings.

You may get an ambulatory reading if your blood pressure reading by your GP is more than 140/90, or if your doctor suspects you may have high blood pressure but your reading in the surgery doesn’t reflect this.

If you’re offered an ambulatory reading, your doctor will fit a blood pressure cuff similar to the one they use in the surgery. This is attached to a small machine that regularly triggers the cuff to inflate, just like it does at the GP. Medicare doesn’t cover this type of blood pressure monitoring. Private health insurance can’t cover it because it’s an outpatient service. Costs vary from around $80 – $200.