A disorder caused by overactivity of the pituitary gland that results in excess amounts of cortisol. This overactivity may be caused by an abnormal growth on the pituitary or from a steroid medication (iatrogenic). Symptoms include extreme weight gain, osteoporosis, hypertension, moodiness, and sleep disturbances. To treat symptoms that are caused by a pituitary tumor, the tumor is surgically removed and patients follow-up with steroid replacement. To treat symptoms that are caused by other steroid medication, patients taper off and eventually stop the medication.