Cushing's disease refers to an endocrine disorder where too much cortisol is produced by the body. It is sometimes difficult for physicians to determine what organ is responsible for the elevated cortisol levels.

  • Inferior Petrosal Sinus Sampling (IPSS): an invasive procedure in which hormone levels are sampled from the veins that drain the pituitary gland to determine whether a pituitary tumor is responsible for Cushing's disease