Contributor: Gordon K. Klintworth
Hypertension (hypertensive cardiovascular disease) is a disorder of the cardiovascular system characterized by a systolic pressure >160mm Hg. or a diastolic pressure  >90mm Hg or both. Hypertension is a major risk factor for atherosclerosis. The disease is an important cause of death and >50% of patients with angina pectoris, stroke, sudden death, and atherosclerotic occlusion of the abdominal aorta and its branches have hypertension. 75% of individuals with a dissecting aneurysm [aneurysm - dissecting] of the aorta, intracerebral hemorrhage [hemorrhage - cerebral] or ruptured wall of the myocardium have hypertension. The cause of 95% of patients with hypertension remains unknown, but genetic factors are important. Known causes of hypertension include renal disease, coarctation of the aorta, and pheochromocytoma. The cardinal lesion in most persons with hypertension is a decreased lumen in the arterioles and small muscular arteries. Chronic hypertension leads to arteriosclerosis and arteriolosclerosis. Severe hypertension commonly affects the retina and causes hypertensive retinopathy.