The Society for Endocrinology describes the function of adrenocorticotropic hormone, or ACTH, as the stimulation necessary to release cortisol. ACTH also helps stimulate the body to produce higher levels of adrenaline and noradrenaline.
ACTH is produced by the pituitary gland after being signaled by corticotrophin-releasing hormone, or CRH, which is produced in the hypothalamus. As stated by the Society of Endocrinology, after ACTH is released from the pituitary gland, the hormone travels to the adrenal glands. The ACTH binds to receptors in the adrenal glands to stimulate the production of cortisol.
WebMD explains that cortisol is a hormone that manages physical and psychological stress. Cortisol levels are critical to sustain life. ACTH and cortisol levels are inversely related. As cortisol levels rise, ACTH levels fall. This is called a negative feedback loop. ACTH levels change throughout the day based on cortisol levels. Typically, ACTH levels are highest in the mornings and lowest in the evenings.
The Society of Endocrinology explains that individuals who do not have regular ACTH levels are at risk for several diseases. For example, high levels of ACTH can lead to Cushing's disease, Addison's disease or congenital adrenal hyperplasia. Low levels of ACTH can lead to Cushing's syndrome.