What is blood pressure ?

Blood pressure is the pressure exerted by the blood on the walls of arteries as heart pumps blood in our body.

How is blood pressure measured ?

Blood pressure is measured in two figures, one higher and one lower. Higher figure represents systolic pressure, which is when heart contracts and blood is forced in the arterial system. Lower figure represents diastolic pressure that is when heart relaxes and takes in the blood. For example- in a reading of 120/80, 120 is systolic and 80 is diastolic pressure.

Blood pressure is measured by tying a cuff around the arm. Its inflated by air until it stops the flow of blood. The pressure is released then, and when the flow begins again, a sound is audible and that is systolic pressure. On release of more pressure, sound faints and that is diastolic pressure.

What is normal blood pressure, and when is it called hypertension ?

Normal blood pressure is less than 120/80. Blood pressure between 120/80 to 139/89 is called pre-hypertension or High normal. And above that i.e. more than 140/90 is considered as hypertension.