If you look for primary aldosteronism, you find it

A condition considered rare is not sought; a condition not sought is not diagnosed; a condition not diagnosed is considered rare…

A diagnostic adage advises that when you hear hoofbeats, you should think “horses”, not “zebras”. This dogma seems to be applied even when standing in the medical equivalent of the African savanna. Accordingly, we may think axiomatically that the default diagnosis should be what is common. Most high blood pressure is idiopathic in nature, and we can fall into the trap of assuming that secondary causes, including primary aldosteronism, are rare and we need not actively look for them.