The term congenital adrenal hyperplasia (CAH) refers to a complex series of rare but well-studied enzymatic errors of metabolism with deficient levels of different enzymes involved in the synthesis of cortisol (hydrocortisone).

CAH comprises a group of disorders resulting from defective synthesis of adrenal corticosteroids. Lack of glucocorticoids, especially cortisol, causes various kinds of metabolic problems. The response to low levels of cortisol is increased production of corticotropin (ACTH