Etiology

Essential HTN in 85-90 %.

Secondary HTN 10-15 %.

Causes:

• Sleep apnea syndrome.
• Renal failure.
• Renovascular HTN.
• Primary aldosteronism.
• Pheochromocytoma.
• Aortic coarctation.
• Cushing syndrome.
• Hypo or hyperthyroidism.