Adreno Cortico Trophic Hormone (ACTH)

• Test Name: Adreno Cortico Trophic Hormone (ACTH) Test
• Test Type: Hormonal blood test
• Specimen Required: Plasma sample from a blood draw
• Methodology: This test measures the concentration of ACTH in the blood, produced by the pituitary gland, which regulates cortisol production by the adrenal glands.
• Purpose: Used to evaluate adrenal gland function and detect disorders related to the hypothalamic-pituitary-adrenal (HPA) axis, such as Addison’s disease or Cushing’s syndrome.

• Diagnosis: Helps in diagnosing adrenal disorders like Addison’s disease (adrenal insufficiency) and Cushing’s syndrome (excess cortisol production).
• Monitoring: Monitors patients with adrenal or pituitary disorders to assess treatment effectiveness or progression of the disease.
• Differentiation: Differentiates between primary and secondary causes of adrenal insufficiency or overactivity (e.g., adrenal gland vs. pituitary gland issues).

• Plasma ACTH Measurement: The test includes measuring the plasma concentration of ACTH.
• Cortisol Levels: Often paired with cortisol testing to provide a comprehensive assessment of adrenal gland function.
• Stimulation or Suppression Tests: This may be part of a dynamic endocrine function test where ACTH stimulation or suppression is monitored over time.

• High ACTH Levels: Indicates conditions such as Addison’s disease, where the adrenal glands do not produce enough cortisol, or ectopic ACTH production seen in certain tumors.
• Low ACTH Levels: Suggests adrenal tumours or pituitary insufficiency (secondary adrenal insufficiency), where the pituitary gland fails to produce enough ACTH.
• Clinical Correlation: Results must be interpreted in conjunction with cortisol levels and clinical symptoms for a complete diagnosis.

• Turnaround Time: Results are typically available within 1-2 days.
• Normal ACTH Range: Reference values vary depending on the time of day (ACTH follows a circadian rhythm), but are generally between 10–60 pg/mL.
• Abnormal Results: Elevated or decreased ACTH levels lead to further diagnostic workups, such as imaging tests or dynamic endocrine tests, to pinpoint the cause of the hormonal imbalance.

Q. What is the ACTH test used for?
The ACTH test measures the level of adrenocorticotropic hormone in the blood and helps diagnose conditions like Addison’s disease or Cushing’s syndrome
 

Q. How is the ACTH test performed?
A healthcare provider draws a blood sample, usually in the morning when ACTH levels are typically at their highest, and the sample is sent to the lab for analysis
 

Q. Why might my doctor order an ACTH test?
Your doctor may order this test if you show symptoms of adrenal dysfunction, such as unexplained weight gain, fatigue, low blood pressure, or abnormal skin pigmentation
 

Q. What do high levels of ACTH indicate?
High levels of ACTH can indicate adrenal insufficiency (e.g., Addison’s disease) or excess ACTH production from a tumour or ectopic source
 

Q. What do low levels of ACTH mean?
Low ACTH levels may suggest an adrenal tumour or secondary adrenal insufficiency due to a pituitary gland problem, which may be affecting ACTH production
 

Q. Do I need to prepare for the ACTH test?
ACTH levels vary throughout the day, so your doctor may ask you to have the test done in the early morning or after fasting. Follow any specific instructions provided by your healthcare provider
 

Q. What are the next steps if my ACTH levels are abnormal?
If your ACTH levels are abnormal, your doctor may order further tests, such as cortisol measurements, imaging of the adrenal or pituitary glands, or dynamic endocrine testing to clarify the cause.