The adrenocorticotropic hormone Test or ACTH - Reasons, Preparations and Method of testing

The adrenocorticotropic hormone or ACTH is produced by the anterior pituitary gland. ACTH is secreted in response to the production of another hormone by the hypothalamus known as corticotropin-releasing hormone or CRH. The adrenocorticotropic hormone function is to stimulate the adrenal glands into producing cortisol which is a glucocorticoid.

Cortisol plays a role in the management of stress by the body. Adrenocorticotropic hormone deficiency occurs when the pituitary gland fails to secrete the hormone or when it produces a lower level of the hormone. This deficiency can arise either due to a specific abnormality or a general dysfunction of the pituitary gland.

Reasons for Performing the Adrenocorticotropic Hormone Test

An ACTH test is performed to determine if the problem is with the pituitary or the adrenal glands as high ACTH levels and low cortisol levels or vice versa can arise due to problems in the adrenal glands. Low levels of both hormones may result from a disruption in the pituitary gland. The test also checks for an increased production of ACTH as this may be caused by over activity of the pituitary gland.

Preparation for Adrenocorticotropic Hormone the Test

In preparation for such a test, one must not eat or drink ten to twelve hours prior to it. Medications can influence the test results and as such the doctor must be informed about all medications that the individual is currently taking. Exercise must also not be engaged in for twelve hours before testing. It is also advisable to avoid mental stress for a twelve hour period before the test. Depending on whether the doctor requires a peak level or a low level of ACTH, he will perform the test either in the morning or evening respectively. ACTH is released from the pituitary gland in spurts and as such its quantity in the blood keeps changing every minute. Any concerns regarding the test and its results can be discussed at length with the doctor.

Method of Testing Adrenocorticotropic Hormone

A blood sample is taken from a vein of the upper arm of the individual.

Test Results

Test results are usually made available after four days. High levels of ACTH may result due to physical or emotional stress, diseases such as cushing’s disease and addison’s disease and presence of tumors in the pituitary or adrenal glands. Low ACTH levels may result due to pituitary gland damage such as tumor, injury or radiation and cushing’s syndrome.

Risk Factors

The risk factor involved in having a blood sample taken is very low. At the most, a bruise or slight swelling will occur around the vein. Bleeding may occur in those with bleeding disorders or those who take blood thinning medications.