"Hypertension is the term used to describe high blood pressure.

Blood pressure is a measurement of the force against the walls of your arteries as your heart pumps blood through your body.

Blood pressure readings are usually given as two numbers -- for example, 120 over 80 (written as 120/80 mmHg). One or both of these numbers can be too high.

The top number is called the systolic blood pressure, and the bottom number is called the diastolic blood pressure.

• Normal blood pressure is when your blood pressure is lower than 120/80 mmHg most of the time.

• High blood pressure (hypertension) is when your blood pressure is 140/90 mmHg or above most of the time."