Diagnosis and treatment of ACTH deficiency

Adrenocorticotropic hormone (ACTH) deficiency is an important condition that can be life threatening if not recognised. It can present either as part of a generalised pituitary dysfunction or as an isolated feature. Although spontaneous isolated ACTH deficiency is rare, acquired deficiency as a result of therapeutic glucocorticoid exposure is common. In both of these situations there can be delays in making an appropriate diagnosis and initiating treatment. This article will review the physiology of ACTH, the features of ACTH deficiency, diagnostic strategies and the principles of treatment.