ACTH
Alternative Names: Serum adrenocorticotropic hormone; Adrenocorticotropic hormone; Highly-sensitive ACTH
An ACTH test measures ACTH, a hormone released from the anterior pituitary gland in the brain.
Why is the Test Performed?
This test can help find the causes of hormone problems.
The main function of ACTH is to regulate the steroid hormone cortisol, which is released by the adrenal cortex.
How is the Test Performed?
Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
The levels of ACTH change with the body's natural 24-hour cycle of processes (circadian rhythms). This test is most accurate if it is performed early in the morning.
Preparation for the Test
The health care provider may advise you to stop taking steroid drugs. You may need to be at the laboratory or office where the blood is being drawn by or before 8 a.m.
How will the Test Feel?
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
ACTH Risks
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample 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
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Considerations
Special handling of the blood sample is required.
Normal Results for ACTH
Normal values: 9 - 52 pg/mL
Note: pg/mL = picograms per milliliter
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
What Abnormal Results Mean
Higher than normal levels of ACTH may be due to:
- Addison's disease
- Adrenoleukodystrophy (very rare)
- Congenital adrenal hyperplasia
- Cushing's disease
- Ectopic tumor producing ACTH
- Nelson's syndrome (very rare)
Lower than normal levels of ACTH may be due to:
- Cushing syndrome related to adrenal tumor
- Exogenous Cushing syndrome
- Pituitary insufficiency
Other conditions under which the test may be performed:
Related Images
Learn more about ACTH
Reviewed By: Ari S. Eckman, MD, Division of Endocrinology and Metabolism, Johns Hopkins School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Copyright 2011 A.D.A.M., Inc.
