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Adrenocorticotropic Hormone (ACTH)

What is Adrenocorticotropic Hormone (ACTH)?

Adrenocorticotropic hormone (ACTH), also known as corticotropin, is a hormone produced by the pituitary gland in response to corticotropin-releasing hormone (CRH) from the hypothalamus. ACTH plays a vital role in stimulating the adrenal glands to produce and release cortisol, a hormone essential for stress response, metabolism, and immune regulation.

Role of ACTH in Cortisol Regulation

ACTH is the primary stimulator of cortisol production in the adrenal cortex. Cortisol and ACTH levels follow a natural daily rhythm, with peak levels typically occurring between 6:00 and 8:00 a.m., and lowest levels around 11:00 p.m. Monitoring both ACTH and cortisol levels is essential for diagnosing various adrenal and pituitary disorders.

Clinical Use of ACTH Testing

ACTH testing is typically performed alongside cortisol tests to help diagnose or monitor conditions related to abnormal cortisol production, including:

Hypercortisolism (Cushing’s syndrome), including:

Cushing’s disease (pituitary origin)

Ectopic ACTH-producing tumours

Ectopic CRH production

Adrenal cortisol-secreting tumours

Adrenal hyperplasia

Hypocortisolism, including:

Addison’s disease (primary adrenal insufficiency)

Secondary adrenal insufficiency (pituitary dysfunction)

Hypopituitarism

Specialist ACTH Testing in Slough

If you are in Slough or the surrounding Berkshire area and are experiencing symptoms related to cortisol imbalance—such as fatigue, weight changes, or blood pressure fluctuations—ACTH testing is available at specialist diagnostic centres. This is a specialist test, and it is important to contact the laboratory in advance for instructions and to schedule an appointment. ACTH testing in Slough provides vital insights for diagnosing adrenal and pituitary conditions and guiding tailored treatment plans.