Blood pressure (BP) is the pressure exerted by circulating blood upon the walls of blood vessel. It is one of the critically important signs of life (vital sign) and is expressed as systolic/diastolic blood pressure. ‘Systolic’ refers to blood pressure when the heart is contracting. Maximum pressure in the arteries during contraction of ventricles is called the systolic blood pressure. Normal blood pressure is less than 120 mmHg/80 mmHg.
A normal systolic blood pressure is 120 or below. A systolic blood pressure of 120-139 is borderline high blood pressure and a pressure of 140 or higher is considered high blood pressure. Borderline high blood pressure is a risk factor for developing heart disease. Blood pressure doesn’t stay the same all the time. It lowers during sleep and rises when awake. Blood pressure also rises when nervous, excited or active.
An elevated systolic blood pressure with a normal diastolic blood pressure is called isolated systolic hypertension. Increased arterial stiffness and build-up of plaque causes an increase in systolic blood pressure with age.