Understanding Your Cortisol Serum (Evening Sample) Test
What It Is: The Cortisol Serum (Evening Sample) test is a blood test that measures the level of cortisol, a crucial steroid hormone produced by your adrenal glands. This test is typically done in the evening because cortisol levels naturally fluctuate throughout the day—peaking in the morning and dropping by evening.
Why It's Done: This test helps diagnose and monitor conditions related to adrenal gland function, such as Cushing’s syndrome (where your body produces too much cortisol) and Addison’s disease (where your body produces too little cortisol).
Why Cortisol Matters: Cortisol is often called the "stress hormone" because it helps your body respond to stress. But its role goes far beyond that:
Regulating Blood Sugar: It helps control your blood sugar levels by influencing how your body uses carbohydrates.
Managing Inflammation: Cortisol has anti-inflammatory properties, helping to reduce swelling and inflammation.
Balancing Electrolytes and Water: It helps regulate the distribution of electrolytes and water in your body.
Blood Pressure Control: Cortisol helps maintain normal blood pressure.
Metabolism: It influences how your body uses fats, proteins, and carbohydrates for energy.
How the Test Works:
Preparation: Typically, you'll need to avoid eating or drinking (except water) for a certain period before the test, as instructed by your healthcare provider.
Sample Collection: A healthcare professional will draw a small sample of your blood in the evening.
Laboratory Analysis: The blood sample is sent to a lab, where the cortisol level is measured.
Interpreting the Results:
Normal Cortisol Levels: Indicate that your adrenal glands are functioning properly.
High Cortisol Levels: Could suggest Cushing’s syndrome, adrenal tumors, or a problem with your pituitary gland, which regulates cortisol production.
Low Cortisol Levels: Could indicate Addison’s disease, adrenal insufficiency, or other disorders affecting adrenal function.
Why Your Doctor Might Order This Test:
Diagnosing Adrenal Disorders: To check for conditions like Cushing’s syndrome or Addison’s disease.
Monitoring Treatment: For individuals diagnosed with adrenal disorders, this test helps monitor how well the treatment is working.
Evaluating Symptoms: If you're experiencing symptoms like unexplained weight gain, fatigue, muscle weakness, or high blood pressure, your doctor may use this test to determine if cortisol levels are the cause.