[Hypertension: the main causes revisited].

Does "essential" mean "ignorance"? The historical demonstration made by Jerome Conn who was the first to describe primary hyperaldosteronism, back in 1954, shows how an outstanding diagnostic route has enlightened our knowledge. Using the examples of hyperaldosteronism and reno-vascular hypertension, a reflex ion is made to arouse our curiosity. In the end, the term "essential" is only the cover-up of what we yet have to learn.