Cushing's syndrome is a hormonal disease caused by the overproduction of certain adrenal hormones, particularly cortisol. In a normal person, the body releases cortisol in measured amounts each day, but in Cushing's patients cortisol is produced almost continuously. Cushing's disease is Cushing's syndrome caused by a tumor on the pituitary gland that causes an excess of ACTH which directly increases cortisol production, and was the cause of Cushing's syndrome in the episode Heavy.