Cortisol Test

What is a cortisol test?

A cortisol test measures the level of cortisol in your body. Cortisol is a hormone your adrenal glands make. The test checks if you have too much or too little of the hormone.

The test may require a sample of one of the following or a combination:

• Blood
• Pee (urine)
• Spit (saliva)

Your healthcare provider may recommend a cortisol test if you have symptoms of certain conditions. The results can help your provider diagnose:

• Addison’s disease. This condition happens when your body doesn’t have enough cortisol.
• Cushing syndrome. This condition occurs when your body has too much cortisol.
• Certain tumors. Various tumors may cause high cortisol levels.

Other names for a cortisol test include:

• Free cortisol
• Salivary cortisol
• Urinary cortisol

How do you test cortisol levels?

Tests can measure cortisol in your blood, pee, spit or a combination. Your healthcare provider will tell you which test they recommend.

You may need to repeat cortisol testing twice in one day or multiple times over several days. This is because your cortisol level naturally varies in a 24-hour period.

Cortisol blood test

You can expect to experience the following during a cortisol blood test:

1. You’ll sit in a chair. A healthcare provider (usually a phlebotomist) will check your arms for an easily accessible vein. This is usually in the inner part of your arm on the other side of your elbow.
2. Once they’ve located a vein, they’ll clean and disinfect the area.
3. They’ll then insert a small needle into your vein to take a blood sample. This may feel like a small pinch.
4. After they insert the needle, a small amount of blood will collect in a test tube.
5. Once they have enough blood to test, they’ll remove the needle. They’ll hold a cotton ball or gauze on the site to stop the bleeding.
6. They’ll place a bandage over the site, and you’ll be finished.

The entire procedure usually takes fewer than five minutes.

Cortisol saliva test

This is usually a take-home test. This is because you may need to take it right when you wake up or at night. Your provider will give you a special kit. They’ll tell you what time to do the test and how to return the sample.

The kit will have specific instructions. But in general, it involves the following steps:

1. Don’t eat, drink or brush your teeth for 30 minutes before taking the test. Also, don’t floss, smoke or vape during this time.
2. Without touching it, drop the swab in your mouth. Wait a couple minutes until it’s soaked with spit.
3. After a couple of minutes, spit the swab out into the test container. Again, don’t touch the swab with your fingers.
4. Follow the instructions for returning the sample to your provider.

Cortisol urine test

Most urinary cortisol tests require collecting all the pee you make in 24 hours. Your provider will give you a container to collect your pee at home. In general, the steps include:

1. The first time you have to pee in the morning, go as you normally would. Don’t collect it. Write down the time as the start time.
2. Every time you pee after that, collect it in the container. Be very careful to get all of your pee into the container. Avoid getting any poop or toilet paper in it. Keep the container in the fridge or a cooler when you’re not using it.
3. Try to collect your pee for the last time as close as possible to 24 hours after you marked the start time. For example, let’s say you have your first pee (that you didn’t collect) at 8 a.m. on a Monday. Try to collect for the last time at 8 a.m. on Tuesday.
4. Make sure the container is marked with your name, start time, end time and any other required information.
5. Drop the container off at the lab as soon as possible. Your provider will tell you where to take it.

How do I prepare for a cortisol test?

Your healthcare provider will give you specific instructions for the type of cortisol test you’re getting. For example, you shouldn’t eat, drink or brush your teeth before a salivary test. You may need to rest beforehand so that stress doesn’t affect the results.

When will I get the results of a cortisol test?

It may take one to five days to get your cortisol test results. It depends on your healthcare provider and lab.

What are normal cortisol levels?

For most tests that measure cortisol levels in your blood, the normal ranges are:

• 6 a.m. to 8 a.m.: 10 to 20 micrograms per deciliter (mcg/dL)
• Around 4 p.m.: 3 to 10 mcg/dL

The level of cortisol in your blood, pee and spit is usually highest in the early morning and declines throughout the day. It reaches its lowest level around midnight. This pattern can change if you work a night shift and sleep at different times of the day.

Normal ranges can vary from lab to lab, time to time and person to person. Your healthcare provider will interpret your results and let you know if you need to get further testing.

What do cortisol test results mean?

The results of cortisol testing can point to several conditions. Your healthcare provider will explain your results and what they mean.

High levels of cortisol might result from:

• Taking large doses of certain medications, like corticosteroids
• A tumor in your pituitary gland that’s making adrenocorticotropic hormone (ACTH), which triggers cortisol production
• A tumor in your adrenal gland that’s making too much cortisol
• A tumor elsewhere in your body, like small cell lung cancer

Low levels of cortisol might result from

• A tumor in your pituitary gland that slows ACTH production
• Underactive or damaged adrenal glands
• An underactive pituitary gland

If my cortisol test results are abnormal, what are the next steps?

Just because you have an abnormal result doesn’t necessarily mean you have a medical condition that needs treatment. Several factors can affect your cortisol levels, like:

• Stress
• Physical activity
• Serious illness
• Hot and cold temperatures
• Certain medications
• When you sleep

Your healthcare provider will go over the results with you. They’ll consider your symptoms and medical history. If they think you need further testing, they may recommend one or more of the following tests:

• ACTH stimulation test. This checks how your adrenal glands respond after you get a shot of synthetic ACTH.
• Dexamethasone suppression test. This measures cortisol after you take a medication called dexamethasone, a manufactured version of cortisol.
• Imaging tests. An MRI or CT scan allows your provider to see your glands and check for a possible tumor.