An idiots guide to.....

What is blood pressure?

Blood pressure is the pressure of blood in your arteries (blood vessels). Blood pressure is measured in millimetres of mercury (mmHg). Your blood pressure is recorded as two figures. For example, 150/95 mmHg. This is said as '150 over 95'.

• The top (first) number is the systolic pressure. This is the pressure in the arteries when the heart contracts.
• The bottom (second) number is the diastolic pressure. This is the pressure in the arteries when the heart rests between each heartbeat.

What is high blood pressure?

High blood pressure is a blood pressure that is 140/90 mmHg or above each time it is taken. That is, the blood pressure is 'sustained' at 140/90 mmHg or above. High blood pressure can be:

• just a high systolic pressure, for example, 170/70 mmHg.
• just a high diastolic pressure, for example, 120/104 mmHg.
• or both, for example, 170/110 mmHg.

However, it is not quite as simple as this. Depending on various factors, the level at which blood pressure is considered high enough to be treated with medication can vary from person to person.

Diastolic Blood Pressure. The diastolic pressure (the lower and second number) is the measurement of force as the heart relaxes to allow the blood to flow into the heart. High diastolic pressure (the second and lower number) is a strong predictor of heart attack and stroke in young adults.