Adrenocorticotropic hormone (ACTH) is a hormone produced by the pituitary gland, located at the base of the brain. Its primary function is to stimulate the adrenal glands to release cortisol, a hormone that helps the body respond to stress, regulate metabolism, and maintain blood pressure. ACTH plays a crucial role in the body's stress response. When the body experiences stress, the hypothalamus signals the pituitary gland to release ACTH into the bloodstream. This, in turn, prompts the adrenal glands to produce cortisol, which helps manage various bodily functions during stressful situations.