It is a hormone produced in the pituitary glands in the anterior (front) part. It is produced in the pituitary glands as a response to biological stresses. The release of this hormone leads to the production of cortisol. It is also related to the sleep rhythms. As a polypeptide hormone, ACTH is also used in diagnostic tests and medications. ACTH also stimulates the secretion of glucocorticoid steroid hormones in the adrenal cortex (See: Adrenal Cortex). It also stimulates other hormones responsible for the production of melanin. ACTH test is done to measure the levels of ACTH hormone and cortisol in blood. It is used to detect diseases like pituitary and adrenal disorders, tumors of the pituitary and adrenal glands, and lung tumors. This test is done by drawing venous blood. This test is also done for people with Cushing’s disease, adrenal hyperplasia, Nelson’s syndrome, and Addison’s disease.