ACTH blood tests are used, usually in conjunction with cortisol tests, to help detect, diagnose, and monitor conditions associated with excessive or deficient cortisol in the body. These conditions include:

·         Cushing disease: excess cortisol that is due to an ACTH-producing tumor in the pituitary gland (usually a benign tumor)

·         Cushing syndrome: refers to the symptoms and signs associated with excess cortisol; in addition to Cushing disease, Cushing syndrome may be due to an adrenal tumor, adrenal hyperplasia, the use of steroid medications, or due to an ACTH-producing tumor located outside the pituitary (ectopic), such as in the lungs.

·         Addison disease (primary adrenal insufficiency): decreased cortisol production due to adrenal gland damage

·         Secondary adrenal insufficiency: decreased cortisol production because of pituitary dysfunction

·         Hypopituitarism: pituitary dysfunction or damage that leads to decreased (or no) hormone production by the pituitary, including ACTH production