Increase in blood pressure (B.P.) above the normal level i.e. above the 120/80 is called hypertension.
Causes of hypertension:
1) Increase in uptake of salts.
2) Due to atherosclerosis and arteriosclerosis.
3) Viscosity of blood is directly proportional to hypertension.
4) Cardiac output is also directly proportional to hypertension.
5) Elasticity of arteries is inversely proportional to hypertension.