ACTH Blood Test – Indications, Procedure, Results

What is a normal ACTH level?

• Between 10 and 60 pg/mL
• Normal values — Plasma corticotropin (ACTH) concentrations are usually between 10 and 60 pg/mL (2.2 and 13.3 pmol/L) at 8 AM.

What does a low ACTH level mean?

• A decline in the concentration of ACTH in the blood leads to a reduction in the secretion of adrenal hormones, resulting in adrenal insufficiency (hypoadrenalism). Adrenal insufficiency leads to weight loss, lack of appetite (anorexia), weakness, nausea, vomiting, and low blood pressure (hypotension).

Why would a doctor order an ACTH stimulation test?

• The ACTH stimulation test is used to diagnose adrenal insufficiency, a condition known as Addison’s disease. It is also used to determine if the pituitary gland is not working properly due to hypopituitarism.

What happens if ACTH is high?

• An increased ACTH result can mean that a person has Cushing disease, Addison disease, overactive, tumor-forming endocrine glands (multiple endocrine neoplasias), or ectopic ACTH-producing tumors. A decreased ACTH result can be due to an adrenal tumor, steroid medication, or hypopituitarism.

When should the ACTH test be done?

• The test is usually done first thing in the morning. ACTH levels are highest when you’ve just woken up. Your doctor will likely schedule your test for very early in the morning. ACTH levels are tested using a blood sample.

What is the function of ACTH?

• Adrenocorticotropic hormone (ACTH) is produced by the pituitary gland. Its key function is to stimulate the production and release of cortisol from the cortex (outer part) of the adrenal gland.

How do you feel during the ACTH stimulation test?

• 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. Why the test is performed: This test is helpful in determining if the adrenal and pituitary glands are normal.

Is ACTH high or low in Cushing’s?

• If these tests show high cortisol levels, the doctor will then measure the ACTH level in the blood. In Cushing’s disease, the cortisol levels are high, and the ACTH levels are normal or high. If these results are seen, the doctor will schedule an MRI of the pituitary gland to pinpoint the location of any tumors.

What type of hormone is adrenocorticotropic hormone?

• peptide hormone
• Adrenocorticotropic hormone (corticotropin; ACTH) is a 39-amino-acid peptide hormone produced by cells of the anterior pituitary gland and carried by the peripheral circulation to its effector organ, the adrenal cortex, where it stimulates the synthesis and secretion of glucocorticoids and, to a more modest extent

Is fasting required for the ACTH test?

• ACTH Test Preparation
• If you take steroids, you’ll need to stop for up to 48 hours before the test. Steroids can affect the test results. Your doctor might ask you to limit your carbohydrates in the 48 hours leading up to the test as well.

Can you drink water before the ACTH test?

• You will need to fast (no food or drinks other than water) after 10:00 pm the night before your test. Please DO drink water the morning of the test. You can bring a snack to eat once the test is completed. Your doctor may also want you to take dexamethasone at 11:00 pm the night before the test.

What stimulates ACTH secretion?

• CRH stimulates the anterior pituitary to release ACTH. ACTH acts on the adrenal cortex to release cortisol and androgens. The increase in cortisol provides a negative feedback system to decrease the amount of CRH released from the hypothalamus.

What causes low ACTH and cortisol?

• It occurs when the pituitary gland is unable to make enough adrenocorticotropin hormone (ACTH). ACTH sends a signal to the adrenal glands and stimulates them to make cortisol. If the pituitary gland does not make enough ACTH, the body will have low levels of cortisol.

What causes low ACTH?

• Isolated ACTH deficiency is caused by damage to the ACTH-producing cells of the pituitary gland and can lead to secondary adrenocortical insufficiency.

What are the symptoms of low ACTH?

• Symptoms include fatigue, weakness, weight loss, nausea, vomiting, and diarrhea, but there is usually less hypovolemia. Diagnosis is clinical and by laboratory findings, including low plasma ACTH with low plasma cortisol.

How does cortisol affect ACTH?

• The adrenal cortex secretes cortisol in response to ACTH. When plasma cortisol increases, it suppresses the release of CRH and ACTH, which, in turn, leads to a lowering of the cortisol level.

How do you treat low ACTH?

• ACTH deficiency. ACTH deficiency can be treated with either hydrocortisone or prednisolone, which is a synthetic corticosteroid drug [³]. In patients with hypopituitarism whose aldosterone levels are approximately normal, there is no need to replace mineralocorticoids.