familial hyperaldosteronism type III (MONDO_0013359) (FH-III) is a rare heritable form of primary aldosteronism (PA) that is characterized by early-onset severe hypertension, non glucocorticoid-remediable hyperaldosteronism, overproduction of 18-oxocortisol and 18-hydroxycortisol, and profound hypokalemia. Also known as: FH-III, FH3, familial hyperaldosteronism type 3.