Cortisol Test: Sample Types, Preparation and Results
Medically reviewed by Dr. Michael Teplitsky, MD Last reviewed 2026-10-20
Cleveland Clinic and MedlinePlus explain sample types, timing windows, and limits
A cortisol test measures hormone levels in blood, saliva, or urine. Cleveland Clinic and MedlinePlus note that timing changes the result and that testing alone cannot diagnose an underlying condition. Preparation requires resting and sharing all medicines with your provider.
A cortisol test measures cortisol, a hormone the adrenal glands make, in blood, urine, saliva or a combination. Cleveland Clinic states that testing may occur twice in one day or over several days. MedlinePlus states that a cortisol test alone cannot diagnose the cause of abnormal levels.
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A cortisol test measures the level of cortisol in your body, a hormone your adrenal glands make. Cleveland Clinic says a provider may recommend a test if you have symptoms of certain conditions. Cleveland Clinic says tests can measure cortisol in your blood, pee, spit or a combination.
Cleveland Clinic reports that you may need to repeat testing twice in one day or multiple times over several days. MedlinePlus states that the most common cause of abnormal cortisol levels is taking steroid medicines for a long time or suddenly stopping them. MedlinePlus lists certain medicines such as birth control pills, along with stress, pregnancy and exercise, among the factors that can affect results.
Blood, Saliva, and Urine Cortisol Tests Compared
MedlinePlus says a health care professional draws blood from a vein in your arm using a small needle. MedlinePlus says blood is usually drawn twice in one day, once in the morning when cortisol is normally at its highest and once in the afternoon when levels are lower. Cleveland Clinic notes that saliva collection is usually a take-home test.
| Sample Type | Collection Method | Timing Window | Source Reference |
|---|---|---|---|
| Blood | Venipuncture from arm vein | Morning peak and afternoon trough | MedlinePlus |
| Saliva | Saliva sample collection | Usually a take-home test | Cleveland Clinic |
| Urine | Container collection of all volume | Full 24-hour collection period | Cleveland Clinic |
Cleveland Clinic states that most urinary cortisol tests require collecting all the urine you make across 24 hours. MedlinePlus says a single morning urine sample may be used in some cases. MedlinePlus reports very little risk from a blood draw and no known risks from saliva or urine tests.
The site's page on at-home hormone testing covers home test kits for hormones.
Why a Provider Orders a Cortisol Test
MedlinePlus says a provider may order a cortisol test if you have symptoms of a condition that affects cortisol levels. MedlinePlus states that high levels may be a sign of Cushing's syndrome. Signs of excessive cortisol include weight gain, a round face, easy bruising, and wide purple streaks on the stomach, breasts, hips, and underarms.
The site's page on high cortisol symptoms covers these signs in more detail.
Cleveland Clinic states that low cortisol levels may come from underactive or damaged adrenal glands or an underactive pituitary gland. MedlinePlus lists symptoms of low cortisol as long-lasting fatigue, muscle weakness, loss of appetite, weight loss, and abdominal pain. Low test values may point to Addison's disease or secondary adrenal insufficiency.
The site's comparison of high versus low cortisol symptoms sets the two presentations side by side. Cleveland Clinic notes that high cortisol levels may come from a tumor in your adrenal gland that is making too much cortisol.
How to Prepare for a Cortisol Test
MedlinePlus explains that stress and exercise can raise cortisol, so you may need to rest before the test. Cleveland Clinic adds that resting beforehand keeps stress from affecting the results. MedlinePlus says to tell your healthcare provider about all medicines used, including skin creams.
MedlinePlus says not to stop using any medicines without talking with your provider first. For a saliva collection, MedlinePlus says not to eat, drink, brush, or floss for 30 minutes before the test. Cleveland Clinic gives the same instruction for a salivary test, and MedlinePlus adds that you may need to stop certain medicines before a saliva test.
What Cortisol Test Results Can and Cannot Tell You
Cleveland Clinic lists blood ranges of 10 to 20 micrograms per deciliter (mcg/dL) from 6 a.m. to 8 a.m. and 3 to 10 mcg/dL around 4 p.m. Cleveland Clinic adds that normal ranges can vary from lab to lab, time to time and person to person. One cortisol value is a snapshot, and MedlinePlus states that a cortisol test alone cannot diagnose the cause of abnormal levels.
Cleveland Clinic notes that an abnormal result does not necessarily mean you have a medical condition requiring clinical treatment. Cleveland Clinic says high levels may come from corticosteroid medications or an adrenal tumor, and low levels from underactive or damaged adrenal glands or an underactive pituitary gland. MedlinePlus says high cortisol that comes and goes in some people, sometimes called pseudo-Cushing's syndrome, can be linked to depression, anxiety, alcohol use disorder, poorly controlled diabetes and obesity.
The site's page on cortisol levels covers what the numbers mean, and its page on the dexamethasone suppression test covers that separate test.
How to test cortisol at home
You don't need a lab appointment to check your own cortisol — a few at-home kits mail you a collection kit and return physician-reviewed results online within days:
Prefer to order direct? The Everlywell Sleep & Stress Test (measures cortisol) uses a CLIA-certified lab, physician-reviewed results, and prepaid return shipping.
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Most stress research uses a standardized root extract (KSM-66 or Sensoril) at 300–600 mg/day. It's generally well tolerated short-term, but ask your doctor if you have a thyroid condition, are pregnant, or take sedatives. Skip 'proprietary blends' that hide the dose, and choose a third-party-tested product.
Frequently Asked Questions
What is a cortisol test?
A cortisol test measures the level of cortisol in your body, using blood, urine, saliva or a combination. Cleveland Clinic notes that cortisol is a hormone your adrenal glands make. MedlinePlus says a provider may order it for symptoms of a condition that affects cortisol levels.
How do you prepare for a cortisol blood test?
Cleveland Clinic and MedlinePlus say you may need to rest beforehand, and MedlinePlus says to tell your provider about all medicines you use. MedlinePlus notes that stress and exercise can raise cortisol, so you may need to rest before. MedlinePlus says to tell your provider about all medicines, including skin creams, and not to stop any medicine without talking with the provider first.
What time of day is a cortisol test done?
Blood testing is commonly done twice in one day, once in the morning and once in the afternoon. MedlinePlus notes that blood is drawn in the morning when levels are highest and again in the afternoon when levels drop. Cleveland Clinic lists its blood ranges for 6 a.m. to 8 a.m. and for around 4 p.m.
Can a cortisol test diagnose Cushing's syndrome or Addison's disease?
A cortisol test alone cannot diagnose the cause of abnormal hormone levels. MedlinePlus states that high levels may be a sign of Cushing's syndrome and low levels may point to Addison disease or secondary adrenal insufficiency. Cleveland Clinic adds that abnormal readings do not automatically mean an individual has a condition requiring treatment.
What can make a cortisol result abnormal?
MedlinePlus states that the most common cause of abnormal cortisol levels is taking steroid medicines for a long time or suddenly stopping them. Other factors that can affect results include birth control pills, pregnancy, exercise, stress, depression, anxiety, obesity, and poorly controlled diabetes.
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