Cortisol Blood Test: What Your Results Mean

What Is a Cortisol Test?

A cortisol test measures how much cortisol is in your blood, urine, or saliva. Cortisol is a hormone made by the adrenal glands, two small glands that sit on top of the kidneys. It helps the body respond to stress, regulate blood sugar, control blood pressure, and manage the sleep-wake cycle.

Cortisol follows a daily rhythm. It is usually highest in the early morning, shortly after waking, and lowest around midnight. Because of that pattern, the time of your sample matters as much as the number itself. A value that looks normal in the morning could be abnormal in the evening.

Testing can be done in several ways. A blood test gives a snapshot at one moment. A 24-hour urine collection or a late-night saliva sample shows the pattern across a day. A clinician chooses the method based on what they are looking for.

Why a Cortisol Test Is Ordered

Cortisol testing is ordered to investigate symptoms that suggest the adrenal system is out of balance:

• Weight gain around the trunk with thin arms and legs
• Easy bruising, purple stretch marks, or a rounded face
• Persistent fatigue, weakness, or dizziness on standing
• High blood pressure or high blood sugar that is hard to explain
• Darkening of the skin or salt cravings
• Monitoring known adrenal or pituitary conditions

Cortisol is often tested with other hormones, including ACTH, a thyroid panel, and testosterone or estradiol, because these systems interact.

What Normal and Abnormal Cortisol Levels Mean

Reference ranges depend on the time of day and the laboratory. A common morning blood cortisol range is about 6 to 23 micrograms per deciliter (mcg/dL). Afternoon values are typically lower, often under 10 mcg/dL.

Stress, illness, injury, pregnancy, and some medications can raise cortisol. A low result can occur with adrenal gland problems or with pituitary conditions that reduce the signal to the adrenals. Because symptoms overlap with many other conditions, cortisol results are read alongside the full clinical picture.

How to Order a Cortisol Test and Where to Get Tested

You can order a cortisol test without a doctor's visit in most US states. Online lab-testing directories let you choose a morning blood test, an AM and PM pair, or a 24-hour urine collection. After paying, you download a requisition and visit a CLIA-certified lab or one of our partner lab locations.

1. Choose the sample type your clinician or the test description recommends.
2. Pay online and print your requisition.
3. Visit a nearby walk-in testing site at the instructed time.
4. Review results in a secure portal, often within two to four business days.

Timing is critical. If your requisition calls for a morning draw, arrive early and try to keep your routine consistent.

How Much Does a Cortisol Test Cost?

A single morning cortisol blood test commonly costs between about $35 and $80 through a direct-access lab. An AM and PM pair often runs $70 to $150. A 24-hour urine cortisol test usually costs $80 to $180 because it includes collection supplies and lab processing. Insurance may cover testing when a clinician documents a medical reason.

Preparation and What to Expect

Prep depends on the sample type. A morning blood draw may require fasting, while a saliva test asks you to avoid certain foods and to collect at set times. A 24-hour urine test requires collecting all urine over a full day.

Tell the lab about any steroids, hormones, or supplements you take, since these can strongly affect cortisol. If a result is abnormal, a clinician may order a follow-up test such as an ACTH stimulation test before making a diagnosis.

Symptoms from the adrenal system can be vague, so results are never read alone. A low morning cortisol with fatigue, weight loss, and dizziness on standing may prompt an ACTH stimulation test, which checks how the adrenal glands respond to a signal. A high late-night cortisol may lead to a dexamethasone suppression test to see whether the normal daily drop is lost.

Do not stop any steroid medication before testing without medical advice, since abrupt changes can be dangerous. If you have severe weakness, very low blood pressure, or confusion, seek urgent care rather than waiting on test results.