Adreno Cortico Tropic Hormone (ACTH)
ACTH is produced by the pituitary glands. It regulates the production of cortisol, which is produced by the adrenal glands. The hypothalamus produces corticotropin-releasing hormone (CRH) that stimulates pituitary gland to produce ACTH. Furthermore, the adrenal gland is stimulated by ACTH and produces cortisol. Therefore, proper functioning of the pituitary, hypothalamus and adrenal glands is essential for the maintenance of appropriate levels of cortisol. Some health conditions interfere with the ACTH and cortisol production in the body and to detect such conditions, ACTH levels are measured in the blood.
Why is the test performed?
An ACTH test is performed to detect conditions affecting the pituitary and adrenal glands and to differentiate them.
When is the test ordered?
The test may be recommended when a person has symptoms suggestive of cortisol deficiency or excess cortisol, which include:
High blood pressure, low potassium and high glucose levels are also observed. Symptoms associated with decreased cortisol production include muscle weakness, weight loss, dizziness, and fatigue. In such persons low BP, low glucose levels; high potassium and low sodium may also be observed.
How is the sample collected?
A blood sample is collected from a vein in the arm.
How to prepare for the test?
The person taking the test may be asked to fast for about 10 to 12 hours before or overnight before the test.
