Medical FIDSAP v2 Practice Test

Cushings syndrome is defined by excess cortisol in the body. The hormone that’s elevated is cortisol, coming from the adrenal cortex in response to too much ACTH (whether from a pituitary source, ectopic ACTH, an adrenal tumor, or from external steroid use). This excess cortisol causes the characteristic features and metabolic effects of the syndrome, and it’s what clinicians look for on testing (for example, elevated 24-hour urinary free cortisol or lack of suppression with a dexamethasone test). The other hormones listed aren’t the primary drivers of Cushings; thyroid hormone and growth hormone aren’t consistently elevated, and insulin may be affected downstream but isn’t the defining elevated hormone.