Primary aldosteronism--actual epidemics or false alarm?

The prevalence of "primary aldosteronism" (PAL) cannot be precisely determined at this time, given 1) lack of a universally accepted definition, and 2) normotensive as well as normokalemic phases in the evolutionary development of a disease eventually characterized by hypertension and hypokalemia. The exception is fully genetically characterised forms such as glucocorticoid-suppressible hyperaldosteronism, the true prevalence of which could be proven today by universal screening using a single blood sample, but this is neither practical nor appropriate. Controversy has arisen regarding the rareness, or otherwise, of PAL because of 1) rediscovery in the last 12 years of the normokalemic phase described by Conn, 2) application of widely available methods for measurement of aldosterone and renin to "screening", 3) variable quality of these methods, and of their application, and 4) lack of the necessary "diagnostic", in addition to "screening", tests in some studies. PAL is significantly more common than previously thought, and a very important potentially curable form of hypertension. Early diagnosis and specific treatment avoids morbidity. The current focus on increased detection is essential, and will help to resolve the question of prevalence.