Adrenocorticotropic hormone (ACTH) is a hormone that stimulates the production of cortisol. Cortisol is a steroid hormone made by the adrenal glands that is important for regulating glucose, protein, and lipid metabolism, suppressing the immune system’s response, and helping to maintain blood pressure.
ACTH is produced by the pituitary gland. Located below the brain in the center of the head, the pituitary gland is part of the endocrine system, a network of glands that work together to produce hormones that act on organs, tissues, and other glands to regulate systems throughout the body.
An increased ACTH result can mean that a person has Cushing syndrom, Addison disease, overactive, tumor-forming endocrine glands (multiple endocrine neoplasia), or ectopic ACTH-producing tumors.
A decreased ACTH result can be due to an adrenal tumor, steroid medication, or hypopituitarism.