How Do You Get Your Cortisol Levels Checked?

Cortisol is a hormone your adrenal glands release in response to stress. It helps regulate your metabolism, reduce inflammation, and manage your sleep-wake cycle. To check your cortisol levels, a doctor typically orders a blood, saliva, or urine test. The right test depends on what condition they suspect, such as Cushing’s syndrome (too much cortisol) or Addison’s disease (too little cortisol).

What Are the Different Types of Cortisol Tests?

There are three main ways to measure cortisol. Each one looks at a different side of how your body produces and processes the hormone.

Blood test. This measures the amount of cortisol in your bloodstream at the exact moment of the draw. Because cortisol levels change throughout the day, a single blood test is most useful when taken at a specific time, usually in the morning.

Saliva test. Saliva contains free cortisol, which is the active form not bound to proteins. This test is often done at home using a collection swab. Doctors frequently use it to check the natural dip in cortisol late at night, which helps diagnose Cushing’s syndrome.

Urine test. A 24-hour urine collection measures the total amount of cortisol your body produces over a full day. This gives a broad picture rather than a single snapshot. It is useful for detecting conditions where cortisol production is consistently too high.

How Do You Get Your Cortisol Levels Checked With a Blood Test?

A blood test is the most common starting point. Your doctor will order it through a standard lab, and a technician draws blood from a vein in your arm.

Timing matters more than anything. Cortisol follows a daily rhythm. Levels peak about 30 to 60 minutes after you wake up, then gradually fall throughout the day. The lowest point is usually around midnight.

Because of this rhythm, a morning blood draw gives the most diagnostic information. A normal morning cortisol level in a healthy adult typically falls between 10 and 20 micrograms per deciliter (mcg/dL), though exact reference ranges vary slightly by lab. If your level is below or above that range, it does not automatically mean you have a disorder. Cortisol spikes with physical stress, illness, and even intense exercise, so a single elevated reading can be misleading.

Your doctor may also order an ACTH blood test at the same time. ACTH is the hormone from your pituitary gland that tells your adrenal glands to produce cortisol. Measuring both together helps identify whether the problem lies in the adrenals or in the pituitary.

How Does a Saliva Cortisol Test Work?

Saliva testing is non-invasive and can be done at home. You receive a kit with small collection tubes and swabs. In the evening, usually around 11 p.m., you chew or place the swab in your mouth to collect a sample. You then mail the sample to a lab in the provided packaging.

Late-night saliva cortisol is one of the most reliable screening tools for Cushing’s syndrome. In healthy people, late-night cortisol is very low. If it stays high when it should be near zero, that is a strong signal of excess production.

Some protocols also collect a morning sample to compare the two. This gives your doctor a sense of your daily rhythm rather than just one point.

Saliva tests are not useful for diagnosing adrenal insufficiency (low cortisol). For that, a blood test is the standard approach.

What Is the 24-Hour Urine Cortisol Test?

This test measures cumulative cortisol output. You collect every drop of urine over a 24-hour period in a large container your lab provides. The container is usually kept refrigerated. You start the collection in the morning, discard the first void, and collect everything after that for the next full day, including the first morning void on day two.

The lab measures total cortisol in the sample. This test is particularly useful when doctors suspect Cushing’s syndrome because it captures the whole day’s production rather than one moment.

Accuracy depends on complete collection. Missing a single void can skew the results. Drinking excessive fluids during the collection can also dilute the sample and produce falsely low readings.

Which Test Should You Ask For?

You do not choose your own test. A doctor selects the test based on your symptoms and medical history. If you are experiencing symptoms like unexplained weight gain, high blood pressure, easy bruising, or muscle weakness, the concern may be high cortisol. If you have fatigue, low blood pressure, dizziness, or darkening skin, the concern may be low cortisol.

For suspected high cortisol, a late-night saliva test or a 24-hour urine test is common first-line screening. For suspected low cortisol, a morning blood test is the standard starting point.

If initial screening is abnormal, your doctor may order a dexamethasone suppression test. This involves taking a small dose of a steroid medication the night before a morning blood draw. In healthy people, this medication suppresses cortisol production. If cortisol remains high afterward, it confirms excess production that is not responding to normal feedback.

How Do You Prepare for a Cortisol Test?

Preparation is straightforward but important. Follow your doctor’s instructions exactly, since even small deviations can affect results.

• Morning blood tests are usually scheduled between 7 a.m. and 9 a.m.
• Avoid intense exercise for 24 hours before the test, as it can raise cortisol.
• Tell your doctor about all medications, including birth control pills, steroids, and antidepressants. Estrogen-containing medications can raise cortisol-binding proteins and inflate blood cortisol readings.
• For saliva tests, avoid eating, drinking, or brushing your teeth for 30 minutes before collecting the sample.
• For urine tests, keep the collection container refrigerated and record the exact start and end times.

What Do the Results Mean?

Normal results do not require any action. Your doctor will tell you if your levels fall within the reference range for your lab.

High cortisol on multiple tests suggests Cushing’s syndrome. This condition requires further imaging, usually an MRI of the pituitary gland or a CT scan of the adrenal glands, to locate the cause. It is a serious condition but treatable.

Low cortisol suggests adrenal insufficiency. This can be primary (Addison’s disease, where the adrenal glands fail) or secondary (where the pituitary fails to signal the adrenals). An ACTH test helps distinguish between the two. Low cortisol is a medical condition that requires ongoing hormone replacement therapy.

One abnormal test is rarely enough for a diagnosis. Cortisol fluctuates naturally, and false positives happen. Doctors typically repeat abnormal tests or order a second type of test to confirm before making any diagnosis.

Can You Test Cortisol at Home?

At-home cortisol test kits are sold online and in some pharmacies. These kits provide the collection materials, and you send your sample to a lab for analysis. The lab returns results to you digitally.

These kits can be accurate for what they measure, but they have limits. They do not provide interpretation. A result that looks out of range may simply reflect normal daily variation, stress, or poor collection technique. Without a doctor interpreting the result in the context of your symptoms, you risk misreading the data.

If you are concerned about cortisol levels, the responsible path is to go through a doctor. They will order the right test at the right time and interpret the result correctly. Home kits are not a substitute for medical evaluation, and no study has confirmed that home testing improves health outcomes.

How Much Does a Cortisol Test Cost?

Cost varies widely depending on your insurance, the lab, and the type of test. A single blood cortisol test may cost between $50 and $200 without insurance. A 24-hour urine test typically costs more, often $100 to $300. Saliva tests are usually in a similar range.

Insurance usually covers cortisol testing when a doctor orders it for a legitimate medical concern. You may have a copay or deductible. If you are paying out of pocket, ask the lab for a price estimate before the test, and ask your doctor whether a less expensive test can answer the same question.