What is blood pressure?
Blood pressure is the pressure of blood pushing against the walls of your arteries. Arteries carry blood from your heart to other parts of your body.
So. What do the two blood pressure numbers mean?
Blood pressure is measured using two numbers:
- First number – called systolic blood pressure – measures the pressure in your arteries when your heart beats
- The second number – called diastolic blood pressure – measures the pressure in your arteries when your heart rests between beats.
If the measurement reads 120 systolic and 80 diastolic, you would say, ‘120 over 80’, or write, ‘120/80 mmHg’.
What is normal blood pressure?
There is no such thing as ‘normal blood pressure’. But for most adults it will be between 110/70 and 140/90.
130/80 is a good average target for most patients, especially if you have diabetes.”
For most people, high blood pressure (BP) is ‘silent’, i.e. you cannot ‘feel’ whether it is high or low.
Why is blood pressure important?
It is because it causes strokes, heart attacks and heart failure, which is why we treat it.
Which number is more important?
Typically, more attention is given to systolic blood pressure (the first number) as a major risk factor for heart attacks and strokes.
However, either an elevated systolic or an elevated diastolic blood pressure reading may be used to make a diagnosis of high blood pressure (hypertension). Both numbers imply an increased risk of these complications. So you and your doctor should attend to both.
Is BP constant or does it vary?
Your blood pressure varies minute and minute, and hour by hour. For example, blood pressure follows a circadian rhythm; it increases on waking in the morning and decreases during sleeping at night. This is why it is important not to make a decision on a single reading of BP. Several measurements are required.
Age and blood pressure
Systolic and diastolic blood pressuree rise steadily with age – systolic more than diastolic – due to the increasing stiffness of large arteries, and long-term buildup of plaque in those arteries.
Summary
We have described what do your blood pressure numbers mean. We hope it is clearer now.
Other resources
10 blood pressure facts
10 blood pressure myths
How to take your own BP
Best blood pressure tablets
Last Reviewed on 23 August 2023