Essential hypertension has no distiquishing underlying cause and that represents about 95% .... some factors that contribute to higher blood pressure. These are arteriosclerosis (or hardening of the arteries), thickening or hypertrophy of the artery wall, and excess contraction of the arterioles (small arteries).
In the remaining 5-10% cases, high blood pressure results from a recognizable underlying problem. This is called secondary hypertension. Some possible causes are a kidney abnormality, tumor of the adrenal gland or congenital defect of the aorta. When the root cause is corrected, blood pressure usually returns to normal. If the root cause cannot be found, then it is Essential HP!