Cortisol, Salivary, Free (24-Hour Average)

Why This Test Matters for Your Health

Salivary cortisol reflects your body’s natural cortisol production, which fluctuates throughout the day. Unlike blood tests, saliva samples are easier to collect and don’t require fasting. This test helps doctors evaluate whether your cortisol levels are consistently too high or too low, which can indicate hormonal imbalances or other health issues.

How the Test Works

You’ll collect saliva samples throughout the day, typically every few hours, into a special container. The samples are then analyzed to measure the free cortisol content. This method avoids interference from proteins that bind cortisol in blood, giving a more accurate reflection of your body’s natural cortisol activity.

When You Might Need This Test

Your doctor may recommend this test if you have symptoms like unexplained weight changes, fatigue, mood swings, or high blood pressure. It’s also used to monitor conditions like Cushing’s syndrome (excess cortisol) or adrenal insufficiency (low cortisol), especially when blood cortisol tests are inconclusive.

What to Expect Before the Test

No special preparation is needed. You’ll simply collect saliva samples at home or in a clinic over a 24-hour period. Follow your doctor’s instructions for timing and storage to ensure accurate results.