Physiological Variations of Blood Pressure

Diurnal variation

Blood pressure is lowest early in the day in the morning and highest in the afternoon.

Age

Blood pressure goes up with age. The systolic blood pressure at different ages.

Infancy      = 80-90 mm Hg

Childhood = 90-110 mmHg

Adult         = 110-120mmHg

Elderly      = 140-150mmHg

Sex

Before the occurrence of menopause in females, both the systolic and diastolic blood pressures are slightly lower than males. After menopause blood pressure may be rather higher than males of the same age.

Body build

Fatty persons tend to have higher blood pressure.

Sleep 

In resting conditions as in sloop, blood pressure is decreased.

Exercise

Light exercise such as walking increase the systolic blood pressure, but decrease the diastolic blood pressure.

In intense exercise, the systolic blood pressure may increase up to 180 mm Hg.

Posture 

Standing causes an increment in both systolic and diastolic blood pressure.

Excitement or emotion

This may cause an increment in systolic blood pressure.

After digestion of food

There is a little rise in systolic blood pressure, but the diastolic blood pressure falls due to vasodilation in specific vessels of the body.

Regulation or control of Blood pressure

The following factors affect and regulate blood pressure. As we know that:

Blood pressure =  Cardiac output x Peripheral resistance

Cardiac output = Stroke volume x heart rate