Understanding High Blood Pressure

 What do the numbers mean?

 

Find out how to understand blood pressure readings and use our blood pressure chart to see how healthy your blood pressure is.

 

What does a blood pressure reading look like?

When you have your blood pressure measured, you will be given two numbers, a top number and a bottom number.

• Systolic blood pressure. This is the first, or top, number. This is the highest level your blood pressure reaches when your heart beats, forcing blood around your body.

• Diastolic blood pressure. The second number, or bottom number, is the lowest level your blood pressure reaches as your heart relaxes between beats.

Blood pressure is measured in millimetres of mercury (mmHg). If the first number is 120 and the second number is 80, this would be written as 120/80mmHg, and you’d call it ‘120 over 80’.

 

This video explains more about systolic and diastolic blood pressure.

 

The blood pressure chart

Once you know your numbers, you can use the blood pressure chart to see what they mean and if your blood pressure is in the healthy range. The chart is suitable for adults of any age, as the cut-off point for diagnosing high blood pressure doesn’t change with age.

 

 

How to use the blood pressure chart

Simply find your top number (systolic) on the left side of the chart and your bottom number (diastolic) on the bottom. Where the two lines meet is your blood pressure.

Download the chart.  Blood pressure chart for adults - PDF [PDF 121KB]

 

 

 

What do the readings mean?

As a general guide:

• 140/90mmHg or over – you may have high blood pressure
Most doctors use 140/90mmHg as the cut off for point for diagnosing high blood pressure (hypertension). This is the point where your risk of serious health problems goes up. They might prescribe medications and advise you to make changes to your lifestyle to bring your blood pressure down.

• 120/80mmHg up to 140/90mmHg – pre-high blood pressure
Also called high-normal blood pressure. This is not high blood pressure, but it is a little higher than it should be and means you could go on to develop high blood pressure. See how you can make healthy changes to your lifestyle to lower it.

• 90/60mmHg up to 120/80mmHg – ideal blood pressure
Also called normal blood pressure. Your blood pressure reading is healthy. At this level you have a much lower risk of heart disease and stroke. Following a healthy lifestyle will help you to keep it in the healthy range.

• 90/60mmHg or lower – you may have low blood pressure
Low blood pressure usually isn’t a problem, but it can sometimes make you feel faint or dizzy or could be a sign of another health problem. 

 

The video below explains how your blood pressure numbers are linked to the risk of stroke and other disease.

Reference.

Blood Pressure