Adrenocorticotropic hormone (ACTH) is a pituitary peptide that stimulates the adrenal cortex to produce cortisol and other glucocorticoids. Released in response to stress and corticotropin-releasing hormone (CRH), ACTH helps regulate metabolism, immune responses, and blood pressure. Cortisol exerts negative feedback on ACTH secretion. Clinically, ACTH levels and stimulation tests assess adrenal and pituitary function.

Low ACTH reduces adrenal cortisol production, causing secondary adrenal insufficiency. Symptoms include fatigue, weakness, weight loss, low blood pressure, dizziness, nausea, hyponatremia and low blood sugar. Causes include pituitary disease or suppression by long-term glucocorticoids. Diagnosis uses morning cortisol, ACTH levels and stimulation tests. Treatment addresses the cause and replaces glucocorticoids as needed.

Adrenocorticotropic hormone (ACTH) primarily stimulates the adrenal cortex to synthesize and secrete cortisol (a glucocorticoid), thereby supporting stress responses, glucose metabolism, blood pressure maintenance, and anti-inflammatory effects. It also has a trophic role, promoting growth, maintenance, and functional integrity of the adrenal cortex to sustain adequate hormone production.

ACTH is concerning when it lies outside the lab reference range. Markedly high levels—several times the upper limit (often >100–200 pg/mL)—suggest primary adrenal failure or ectopic ACTH production. Very low levels (commonly <5–10 pg/mL) point to secondary/tertiary adrenal insufficiency. Interpret with morning timing, symptoms, cortisol results and specialist review; different labs use different units and cutoffs.

Yes. Low ACTH reduces cortisol production (secondary adrenal insufficiency), and inadequate cortisol commonly causes persistent fatigue, weakness, weight loss, low blood pressure, and low sodium. Causes include pituitary disease or long-term steroid suppression. Diagnosis uses morning cortisol, ACTH levels, and stimulation tests; treatment is glucocorticoid replacement and addressing the underlying pituitary problem—see a physician for testing and management.

ACTH (adrenocorticotropic hormone) stimulates adrenal cortisol release, driving the body’s stress response. Elevated ACTH (and resulting cortisol) alters arousal, mood, cognition and sleep, and can increase anxiety, irritability, and risk of depressive symptoms; chronic excess contributes to fatigue, memory and concentration problems. Conversely ACTH deficiency is linked to low energy, reduced motivation and depressive moods. Behavioral effects reflect downstream cortisol changes.