Cortisol, Serum (8 AM)

Why This Test Matters

Cortisol is a key hormone produced by your adrenal glands, responding to stress. Low levels may suggest adrenal problems, while high levels could indicate overproduction or other health concerns. This test is often used to diagnose conditions like Addison’s disease or Cushing’s syndrome, which can affect how your body handles stress and hormones.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test to get an accurate reading. Your blood will be drawn from a vein in your arm, and you may feel a brief pinch. If you’re taking medications that affect cortisol, let your doctor know.

What the Results Mean

Results are typically compared to your baseline or to reference ranges for your age and health status. Abnormally low or high levels may signal underlying issues that require further evaluation, such as imaging or additional hormone tests.

Common Conditions Linked to Cortisol Levels

Low cortisol can cause fatigue, weight loss, salt cravings, or dizziness, while high cortisol may lead to weight gain (especially in the face), muscle weakness, or mood changes. Your doctor will interpret results in the context of your symptoms and medical history.