text: what is cushings syndrome?   (m)  cushing's syndrome or hypercortisolism or hyperadrenocorticism is an endocrine disorder caused by excessive levels of the endogenous corticosteroid hormone cortisol. it may also be induced iatrogenically by treatment with exogenous corticosteroids for other medical conditions. it was discovered by american physician, surgeon and endocrinologist harvey cushing (1869-1939) and reported by him in 1932.  cushing's syndrome is also a relatively common condition in domestic dogs in which causes are the same as the syndrome in humans.