Background     Causes Primary causes: Essential HTN (i.e. idiopathic). Commonest cause. Non-pathologically raised during pain or anxiety (including white coat HTN). However, this may suggest underlying problem so consider following up. Kidney diseases (80% of secondary HTN): Chronic kidney disease. Renal artery stenosis: due to atherosclerosis or fibromuscular dysplasia. Latter most commonly occurs in young women, but even then essential HTN is still commoner. Endocrine: Conn's Cushing's Pheochromocytoma Acromegaly Hyperparathyroidism Other: Obstructive sleep apnoea Pregnancy or pre-eclampsia. Coarctation of the aorta. Medication: CE-LESS ('see less'): C yclosporin E strogen (OCP) L iquorice E PO S teroids S ympathomimetics: α-agonists, dopamine agonists, cocaine, amphetamines, and nasal decongestants such as ephedrine. Signs and symptoms Symptoms of HTN itself are rare, and occur only in severe disease. They include heada...