Resistant hypertension: a methodological approach to diagnosis and treatment.

Resistant hypertension affects approximately 10% of the hypertensive patient population. It should be differentiated from white-coat hypertension and pseudo-resistant hypertension. Non-compliance to anti-hypertensive therapy remains the most common cause of resistant hypertension. Primary hyperaldosteronism is not as uncommon as previously thought, but its prevalence depends on the selected population. Low-renin resistant hypertension responds to aldosterone blockade when other drugs are apparently inadequately effective. Sleep apnea syndrome can also contribute to the development of resistant hypertension by stimulating aldosterone secretion, which leads to vascular damage and may promote scarring through more direct actions. Normal blood levels of potassium in resistant hypertension do not exclude the possible presence of hyperaldosteronism.