ACTH Stimulation Test

ACTH levels in the blood may need to be measured in order to determine if someone has a medical condition that affects their cortisol levels. The test use to measure these levels is called the ACTH stimulation test or ACTH stim test for short. Doctors can use this test in conjunction with other laboratory and diagnostic tests to diagnose and treat medical conditions that have an impact on their patients. Learning about the ACTH stimulation test can help you to understand why your doctor has ordered it and how the results will be used.

The ACTH stim test measures the level of cortisol in the blood. There is an established range for what is considered normal. An ACTH stim test result that shows excessive levels of cortisol or too little cortisol can indicate that a person has a medical condition that needs to be treated. Some of the medical conditions that can be diagnosed using the ACTH stimulation test include Cushing's disease, Addison's disease, adrenal insufficiency, and pituitary gland dysfunction.

The ACTH stim test can be ordered if a patient shows signs or experiences symptoms that indicate the presence of a condition that results in an abnormal cortisol level. Signs and symptoms of excess cortisol include obesity, a rounded face, muscle weakness, excess body hair, and acne. These can be accompanied by hypertension, high blood sugar, and low potassium levels. Insufficient levels of cortisol can cause muscle weakness, fatigue, weight loss, and a lack of appetite. These can be accompanied by hypotension, low blood sugar, high calcium levels, and high potassium levels. Doctors will order an ACTH stimulation test if these signs and symptoms are present and are not indicative of other conditions.

Once an ACTH stim test has been performed, the results can be used in conjunction with the results of a cortisol test to determine if a patient has Cushing's disease, Addison's disease, or a tumor that produces ACTH. Low levels of ACTH can indicate adrenal tumors or pituitary dysfunction. The ACTH stimulation test results can be difficult to interpret when used alone. This is why physicians use this test along with other tests to make the best diagnosis possible. Once a medical condition is diagnosed, a patient may be placed on medication therapy to correct abnormal cortisol levels. The ACTH stimulation test may be repeated to help doctors monitor how well patients are responding to their medications.

Lab Tests Online. ACTH: The Test. Retrieved March 31, 2009.