About the Test
Purpose of the test
Cortisol testing helps your doctor determine whether the adrenal glands are producing an appropriate amount of the hormone. Measurements of cortisol may be used to diagnose or monitor certain health conditions.
Diagnostic testing helps find the cause of symptoms. Cortisol testing can help diagnose or rule out conditions that cause abnormal cortisol levels, such as:
- Cushing’s syndrome, a condition characterized by high levels of cortisol
- Cushing’s disease, a type of Cushing’s syndrome in which an excessive amount of a hormone called adrenocorticotropic hormone (ACTH) causes the overproduction of cortisol
- Addison disease, a disorder in which the adrenal glands don’t produce sufficient hormones like cortisol
Monitoring tests are used to understand how your health changes over time. Cortisol testing monitors the effectiveness of treatment if you have unusually low or high cortisol levels.
What does the test measure?
Testing measures the cortisol hormone in the blood, urine, or saliva. Cortisol is one of several glucocorticoid hormones that help the body control blood sugar levels, respond to stress, and regulate the immune system.
It is normal for cortisol levels to change over the day and react to various stressors. The body’s process of producing cortisol requires several steps:
- An area of the brain called the hypothalamus produces the corticotropin-releasing hormone (CRH).
- CRH travels to another part of the brain called the pituitary gland and triggers the secretion of corticotropin, also called ACTH.
- Finally, ACTH is transported to the adrenal glands, where it stimulates the production of cortisol.
In this way, cortisol levels reflect whether these different steps are being carried out normally in the body. Additional information may be gathered by conducting a cortisol test and other tests like the ACTH test.
When should I get this test?
Your doctor may recommend cortisol testing if they think you have a condition affecting your cortisol levels.
Doctors may initiate cortisol testing if you have a health problem unusual for people your age, such as young adults with hypertension or osteoporosis. They may also recommend cortisol testing if you have a severe health condition affecting cortisol levels or if your doctor finds an adrenal tumor during imaging tests conducted for an unrelated concern.
Your doctor may recommend cortisol testing based on your symptoms, especially if you have more than one symptom of high cortisol that worsens with time. Symptoms of high cortisol include:
- Unexplained weight gain, particularly in children
- Fat accumulation around the base of the neck
- A hump-like pad of fat between the shoulders
- Slow growth in children
- Unexplained growth of facial or body hair
- Menstrual periods that are irregular or stop entirely
- Erectile dysfunction
- Lowered fertility and decreased interest in sex in men or people assigned male at birth
- High blood pressure
- High blood sugar
Cortisol testing may also be recommended if you’re experiencing symptoms of low cortisol or if doctors suspect that you may be experiencing acute adrenal crisis, a medical emergency due to insufficient cortisol. Symptoms of low cortisol include:
- Chronic fatigue
- Muscle weakness
- Appetite loss
- Unexplained weight loss
- Abdominal pain
Conditions that cause high and low cortisol levels are rare, and other diseases most often cause these symptoms. Thus, a doctor may test for more common conditions before initiating cortisol testing.
In addition to diagnostic testing, cortisol may be tested as a type of monitoring if you have been previously diagnosed with high cortisol and are taking medications to lower your cortisol levels.
Finding a Cortisol Test
How can I get a cortisol test?
Cortisol testing is typically prescribed by a doctor and performed in a medical setting, like a doctor’s office, hospital, or laboratory. However, you can also get tested without a doctor’s order through services such as a local testing facility.
Can I take the test at home?
There are commercially available at-home cortisol tests. These tests involve collecting blood, urine, or saliva samples and mailing them to a laboratory for analysis. Because cortisol levels change throughout the day, some tests require samples to be collected in the morning, while others use samples taken at several different times during the day.
At-home cortisol tests may also be called at-home stress and sleep panels and measure other substances affecting sleep and the body’s stress responses.
These at-home tests can provide a snapshot of cortisol levels, but they cannot replace physician-ordered tests. A doctor’s evaluation of your symptoms is very important when investigating potential problems with cortisol levels.
How much does the test cost?
The cost of a cortisol test depends on several factors, including:
- Whether the test uses blood, urine, or saliva
- Whether the test is done alone or in combination with other tests
- Whether the test is repeated
- Where the test is performed
- Whether you have health insurance and, if so, the details of your health insurance coverage
Total charges for cortisol testing can include fees for office visits, blood draws, and/or laboratory analysis. Insurance may cover all or some of these charges, but you may be responsible for deductibles or copayments. Talk with your doctor’s office and health insurance provider for detailed information about the costs of cortisol testing.
If you do not have health insurance, talk with your doctor or a hospital administrator about cost estimates and whether any programs are available to reduce testing costs if you are uninsured.
Taking a Cortisol Test
Cortisol can be measured in the blood, saliva, or urine. Because cortisol levels change throughout the day, your doctor will likely recommend that your test be conducted at a specific time, depending on the test’s purpose.
Blood samples for cortisol tests are often collected early in the morning when the cortisol level in your blood should be at its highest. The blood sample is usually taken from your arm at a medical office, hospital, or lab.
Saliva for a cortisol test may be collected at a medical office or home. When testing for high cortisol, your doctor may instruct you to collect a saliva sample late at night while at home.
For a cortisol urine test, you will be provided with containers and detailed instructions on collecting all the urine you produce in 24 hours, after which you will return it to a lab. For convenience, you may choose a 24-hour period when you expect to be at home.
Before the test
Because cortisol levels can vary throughout the day, it is important to inform your doctor if you have an atypical sleep schedule.
Your doctor may ask you to temporarily stop taking certain medications that can interfere with getting an accurate test result. You may also be asked to refrain from vigorous exercise in the day leading up to the test.
During the test
For blood testing, a sample is usually taken from a vein in your arm. The person taking the sample will increase blood in the veins by tying an elastic band around your upper arm. They will clean the skin with an antiseptic, insert a needle into your vein, and draw a small amount of blood into a tube attached to the needle. A blood draw can cause a stinging sensation when the needle pierces the skin, but the process usually takes less than five minutes.
For saliva testing, you will start by rinsing your mouth. Sometimes, you may be told to chew on gum or cotton to stimulate saliva production. You will then spit into a collection container or use a swab to collect saliva, which usually takes just a few minutes and may be done at a laboratory or home. Some patients may be asked to take multiple saliva samples over several days, then return the samples to the testing facility all together.
Urine cortisol testing typically requires a 24-hour urine sample. You will collect all the urine you produce over 24 hours. The laboratory will provide you with one or more containers and instructions on collecting your urine. Follow the instructions you are given exactly as they are written. This process typically starts on one morning and ends the following morning.
After the test
Once a blood sample is collected, the place where the needle entered your arm will be bandaged. After this, you can usually resume your normal activities. You may feel some soreness or have light bruising, but this should go away quickly.
If saliva samples for cortisol testing are being collected at home, return the samples to the testing facility within the recommended period.
After the last urine sample in the 24 hours is collected, seal the container and bring it to the laboratory or your health care provider.
After a urine or saliva cortisol test is complete, there are no side effects or restrictions on activity.
Cortisol Test Results
Receiving test results
Depending on the purpose of testing, you may receive your cortisol test results through a secure online platform or a letter in the mail. Your doctor may call to share your results or discuss them during a follow-up appointment. Cortisol test results are typically available within a few business days.
It is important to remember you may be asked to repeat cortisol tests several times or to take additional follow-up tests before any diagnosis is reached.
Interpreting test results
Cortisol test reports will show the amount of cortisol measured in the test sample and include reference ranges, which are the expected level of cortisol in healthy people. But your individual circumstances must be taken into consideration when interpreting a cortisol test.
For some patients, a single cortisol test with results within the normal range is sufficient evidence that their body produces the correct amount of cortisol. Other patients may need multiple tests to determine if the amount of cortisol in their bodies is normal or abnormal.
Conditions that can cause high cortisol levels, also known as hypercortisolism, include:
- Cushing’s syndrome, a hormonal disorder often caused by high dosages or prolonged use of steroid medications, such as prednisone, dexamethasone, and prednisolone
- Ectopic Cushing’s syndrome, a condition in which the hormone ACTH is made in a tumor in another part of the body
- Cushing’s disease, a condition in which noncancerous tumors on the pituitary gland make too much ACTH
- Rare genetic syndromes
- A tumor in the adrenal gland that produces cortisol
- Other health conditions like pregnancy, obesity, physical and psychological stress, depression, diabetes, alcoholism, and sleep apnea.
Conditions that can cause low cortisol levels include:
- Addison’s disease, also called primary adrenal insufficiency, in which the adrenal glands are damaged and cannot produce enough cortisol and other adrenal hormones
- Secondary adrenal insufficiency, a condition in which the pituitary gland makes insufficient ACTH
- Tertiary adrenal insufficiency, which describes a problem with the part of the brain that produces corticotropin-releasing hormone (CRH)
Abnormal cortisol levels and the conditions that cause them can be challenging to diagnose because the symptoms of low and high cortisol are common in other diseases.
Your doctor is in the best position to help you understand your cortisol test results. It could be helpful to ask specific questions, such as:
- Is this cortisol test result within the reference range?
- What does the result of this cortisol test say about my health?
- Are you able to make a diagnosis based on this test result?
- Do you recommend any additional tests? Why or why not?
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