Secondary Hypertension

Hypertension is a major risk factor for the development of cardiovascular disease. The prevalence of secondary hypertension, 10% is known as a common cause of resistant hypertension. Development of diagnostic technology and the aging is likely to be increased of the prevalence. Secondary hypertension, if it is not appropriate etiologic treatment may sometimes be fatal, as well as to the proper treatment be treatable or curable hypertension. Secondary causes of hypertension include a greater prevalence of obstructive sleep apnea, renal parenchymal disease, renovascular disease and primary aldosteronism. Uncommon secondary causes include pheochromocytoma, Cushing's syndrome, hyperparathyroidism and thyroid disease. Clinical clues for secondary hypertension is onset of hypertension in persons younger than age 20 or older than age 50 without family history of hypertension, poor response to therapy, worsening of control in previously stable hypertensive patient, markedly elevated blood pressure or hypertension with severe endorgan damage, presence of abdominal bruit (renal artery stenosis), moon face and abdominal striae (Cushing's syndrome), paroxysmal headaches and palpitations (pheochromocytoma), pronounced hypokalemia due to low dose diuretic therapy (primary aldosteronism), acute renal failure or hypokalemia after initiation of angiotensin converting enzyme inhibitors or angiotensin II receptor blocker (renal artery stenosis), hypercalcemia (hyperparathyroidism), snoring and daytime somnolence (obstructive sleep apnea). A combination of a good history and physical examination, astute observation, and accurate interpretation of available data usually are helpful in the diagnosis of a specific causation. This article provides an overview of the range of secondary hypertension, including key clinical features, appropriate diagnostic approach and treatment for primary physician.