Does this test have other names?
Urine free cortisol test
What is this test?
A urine cortisol test may help in the diagnosis of two fairly uncommon medical conditions: Cushing's syndrome and Addison's disease. The test also screens for other diseases that affect your pituitary and adrenal glands. It does so by measuring your urine level of a stress hormone called cortisol.
Cortisol is a steroid hormone made by your adrenal glands. It helps your body respond to stress, regulate blood sugar, and fight infections. In most people, cortisol levels are highest in the morning when they wake up and lowest around midnight. Your body also pumps out excess cortisol when you're anxious or under intense stress, which can affect your health if the levels stay too high for too long. If your cortisol levels are too high or too low, you may have a condition that needs treatment.
Why do I need this test?
You may need this test if your healthcare provider suspects a medical problem caused by too much or too little cortisol.
A high cortisol level could be a sign of Cushing's syndrome. Symptoms of Cushing's syndrome include:
Obesity, especially in the torso, face, and neck, with thinner arms and legs
High blood pressure
High blood sugar
Thin skin that bruises easily
Pink or purple streaks on the stomach, thighs, or buttocks
For women, irregular menstrual periods and excess hair on the face and chest
Too little cortisol could be a sign of Addison's disease, also called primary adrenal insufficiency. It could also be a sign of another problem with your adrenal glands. This may cause these symptoms:
Muscle and joint pain
Fatigue, or extreme tiredness
Low blood pressure
Abdominal (belly) pain
Nausea and/or vomiting
Dark patches of skin
For women, decreased armpit and pubic hair and decreased sexual desire
What other tests might I have along with this test?
Besides a urine test for cortisol, your healthcare provider may test the cortisol levels in your blood or saliva.
Your doctor will likely order blood tests that measure your body's response to certain hormones to help determine the cause of your abnormal cortisol levels.
You may also have tests to look inside your body for abnormal growths or tumors. These can affect cortisol levels. Tests may include:
What do my test results mean?
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.
Normal values for cortisol in a urine test are 10 to 110 micrograms per day (mcg/day).
If your urine test reveals abnormally high levels of cortisol, you may be diagnosed with Cushing's syndrome. If your cortisol levels are low, you may have Addison's disease.
How is this test done?
This test requires a urine sample. If your doctor needs a 24-hour sample, he or she will give you detailed instructions about how to collect all of your urine over a 24-hour period.
Does this test pose any risks?
A urine test poses no known risks.
What might affect my test results?
Cortisol levels may be high in people with psychiatric disorders, alcoholism, or morbid obesity. This may be called "pseudo-Cushing state."
How do I get ready for this test?
You don't need to prepare for this test.
- Hanrahan, John, MD
- Taylor, Wanda, RN, Ph.D.