W.H.O define HTN as systolic BP equal to greater than 160 mm of Hg and /Or Diastolic pressure equal to or greater than 95 mm of Hg.
There are Two types of HTN :
Essential (or) Primary where exact cause is not known.
Secondary due to disease of kidney, adrenal, glands, narrowing of AORTA, Pregnancy.
25 % of adults have HTN in industrialized countries India 59.9 to 69.9 per 1000 in males and females in urban population and 35.5 to 35.9 per 1000 in rural population.