ACTH blood test
The ACTH test measures the level of adrenocorticotropic hormone (ACTH) in the blood. ACTH is a hormone released from the pituitary gland at the base of the brain.
How the Test is Performed
Blood sample is needed
Venipuncture is the collection of blood from a vein. It is most often done for laboratory testing.
Read Article Now Book Mark ArticleHow to Prepare for the Test
Your health care provider will likely ask you to have the test done early in the morning. This is important because cortisol level varies throughout the day.
You may also be told to stop taking medicines that can affect the test results. These medicines include glucocorticoids such as prednisone, hydrocortisone, or dexamethasone. Do not stop these medicines unless instructed by your provider.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.
Why the Test is Performed
The main function of ACTH is to regulate the glucocorticoid (steroid) hormone cortisol. Cortisol is released by the adrenal gland. It regulates blood pressure, blood sugar, the immune system, and the response to stress.
Adrenal gland
The adrenal glands are two small triangle-shaped glands in the upper abdomen. One gland is located on top of each kidney.
Read Article Now Book Mark ArticleThis test can help find the causes of certain hormone problems.
Normal Results
Normal values for a blood sample taken early in the morning are 9 to 52 pg/mL (2 to 11 pmol/L).
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different specimens. Talk to your provider about the meaning of your specific test results.
What Abnormal Results Mean
A higher-than-normal level of ACTH may indicate:
- Adrenal glands not producing enough cortisol (Addison disease)
Addison disease
Addison disease is a disorder that causes the adrenal glands to not produce enough hormones.
Read Article Now Book Mark Article - Adrenal glands not producing enough hormones (congenital adrenal hyperplasia)
Congenital adrenal hyperplasia
Congenital adrenal hyperplasia is the name given to a group of inherited disorders of the adrenal gland. Inherited means the traits are passed down ...
Read Article Now Book Mark Article - One or more of the endocrine glands are overactive or have formed a tumor (multiple endocrine neoplasia type I)
Multiple endocrine neoplasia type I
Multiple endocrine neoplasia (MEN) type I is a disease in which one or more of the endocrine glands are overactive or forms a tumor. It is passed do...
Read Article Now Book Mark Article - Pituitary is making too much ACTH (Cushing disease), which is usually caused by a non-cancerous tumor of the pituitary gland
Cushing disease
Cushing disease is a condition in which the pituitary gland releases too much adrenocorticotropic hormone (ACTH). The pituitary gland is an organ of...
Read Article Now Book Mark Article - Rare type of tumor (lung, thyroid, or pancreas) making too much ACTH (ectopic Cushing syndrome)
Ectopic Cushing syndrome
Ectopic Cushing syndrome is a form of Cushing syndrome in which a tumor outside the pituitary gland produces a hormone called adrenocorticotropic hor...
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A lower-than-normal level of ACTH may indicate:
- Glucocorticoid medicines are suppressing ACTH production (most common)
- Pituitary gland not producing enough hormones, such as ACTH (hypopituitarism)
Hypopituitarism
Hypopituitarism is a condition in which the pituitary gland does not produce normal amounts of some or all of its hormones.
Read Article Now Book Mark Article - Tumor of the adrenal gland that produces too much cortisol
Tumor of the adrenal gland
Cushing syndrome due to adrenal tumor is a form of Cushing syndrome. It occurs when a tumor of the adrenal gland releases excess amounts of the horm...
Read Article Now Book Mark Article - A normal response after taking the low-dose dexamethasone suppression test
Risks
There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Multiple punctures to locate veins
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Reviewed By
Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Guber HA, Oprea M, Russell YX. Evaluation of endocrine function. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 25.
Melmed S. Pituitary masses and tumors. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 9.
Newell-Price JDC, Auchus RJ. The adrenal cortex. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 15.