Cushing disease is a specific type of Cushing syndrome, caused by a pituitary tumor. Pituitary tumor affacts the body in a way that it produces too much cortisol. The symptoms can be mild or severe and may include tiredness, weight gain, and diabetes. If left untreated, Cushing disease can lead to serious complications including heart disease, diabetes, osteoporosis, and depression.
Cushing disease is the most common form of endogenous (from the body) Cushing syndrome, and makes up about 70% of Cushing syndrome cases. The other 30% of cases are due to exogenous causes, which includes adrenal tumors (adenomas and carcinomas), pituitary tumors (prolactinomas, somatotropinomas, or growth hormone-secreting adenomas), ectopic adrenocorticotropic hormone (ACTH) secreting tumors, and ACTH-producing tumors of extra-pituitary origin.