Adrenocorticotropic Hormone (ACTH) Blood Test

What is the purpose of this test?

Order this Adrenocorticotropic Hormone (ACTH) Blood Test, which measures the ACTH levels in the blood to diagnose conditions associated with abnormal cortisol levels. The endocrine system produces a hormone called ACTH in the pituitary gland. When cortisol levels are low, the hypothalamus stimulates the production of ACTH, which in turn prompts the adrenal glands to produce cortisol. Issues with the hypothalamus, pituitary, or adrenal glands can disrupt the regulation of ACTH and cortisol production, leading to either excess or insufficient cortisol. To identify, diagnose, and monitor conditions related to excessive or deficient cortisol in the body, healthcare providers use the ACTH blood test alongside cortisol tests.

Some conditions that can be identified with this test include:

• Cushing's disease
• Cushing's syndrome
• Addison's disease
• Secondary adrenal insufficiency
• Hypopituitarism

Measuring ACTH and cortisol can help differentiate among some of these conditions because the level of ACTH changes typically in the opposite direction to the cortisol level. If abnormal levels are detected, a healthcare provider may recommend further testing to help confirm the findings and determine the cause.

When should I order an Adrenocorticotropic Hormone (ACTH) Blood Test?

Individuals may order this test if they have experienced symptoms related to abnormal cortisol levels. Symptoms of excess cortisol include:

• Sudden weight gain
• Buildup of fat in the shoulders
• Stretch marks on the abdomen, thighs, or breasts
• Easily bruising
• Increased body hair
• Muscle weakness
• Fatigue
• Acne

Symptoms of insufficient cortisol include:

• Sudden weight loss
• Nausea or vomiting
• Diarrhea
• Abdominal pain
• Dizziness
• Hyperpigmentation
• Salt craving
• Fatigue