Indications : The test is ordered to detect:
Hormonal imbalances in the body
Problems of the pituitary, such as Hypopituitarism
Problems of the adrenal gland
Cause of tumors in the body
Multiple endocrine neoplasia
The blood sample for the test is acquired early in the morning, before 8 am through venipuncture. Do not eat or drink prior to the ACTH test. Avoid taking steroid - containing medications prior to the test. Consult your doctor for specific details.
Physiology : ACTH is a hormone released from the anterior pituitary gland in the brain. It is released in response to another hormone released by the hypothalamus called corticotropin-releasing hormone (CRH).
To counter the increase in ACTH the cortex layer of the adrenal glands produces a steroid hormone, the cortisol, which help to counter stress. The main function of ACTH is to regulate the production of cortisol.
ACTH levels fluctuate in accordance with circadian rhythm of the human body. When ACTH levels increase the cortisol levels increase and vice versa. The ACTH test is done to detect problems in the pituitary gland and the adrenal glands.
Normal Range : ACTH,Morning-25-50pg/ml,evening-0-50pg/ml
Interpretation : Normal
|Normal ACTH levels1|
|Morning||< 80 pg/mL or < 18 pmol/L|
|Evening||< 50 pg/mL or < 11 pmol/L|
Higher-than-normal levels of ACTH may indicate the following:
Addisons disease - low cortisol
Congenital adrenal hyperplasia - a condition seen at birth
Cushings syndrome - causes tumors in pituitary gland, thyroid, pancreas, lungs or in other parts of the body
Emotional or physical stress
Lower-than-normal levels of ACTH may indicate:
Damage to Pituitary gland due to surgery, stroke, radiation, head injury, or a tumor
Adrenal gland tumors or tumors in other parts of the body
References : +