Adrenocorticotropic Hormone (ACTH)

What is an adrenocorticotropic hormone (ACTH) test?

This test measures the level of adrenocorticotropic hormone (ACTH) in the blood. ACTH is a hormone made by the pituitary gland, a small gland at the base of the brain. ACTH controls the production of another hormone called cortisol. Cortisol is made by the adrenal glands, two small glands located above the kidneys. Cortisol plays an important role in helping you to:

• Respond to stress
• Fight infection
• Regulate blood sugar
• Maintain blood pressure
• Regulate metabolism, the process of how your body uses food and energy

Too much or too little cortisol can cause serious health problems.

Other names: Adrenocorticotropic hormone blood test, corticotropin

What is it used for?

An ACTH test is often done along with a cortisol test to diagnose disorders of the pituitary or adrenal glands. These include:

• Cushing’s syndrome is a disorder in which the adrenal gland makes too much cortisol. It may be caused by a tumour in the pituitary gland or the use of steroid medicines. Steroids are used to treat inflammation but can have side effects that affect cortisol levels.
• Cushing’s disease is a form of Cushing’s syndrome. Cushing’s disease is usually caused by a noncancerous tumour of the pituitary gland. The tumour makes too much ACTH. This causes the adrenal glands to make too much cortisol.
• Addison disease is a condition in which the adrenal gland doesn’t make enough cortisol.
• Hypopituitarism is a disorder in which the pituitary gland does not make enough of some or all of its hormones.