Cortisol in Urine
How It Is Done
24 hour urine
- You start collecting your urine in the morning. When you first get up, empty your bladder but do not save this urine. Write down the time that you urinated to mark the beginning of your 24-hour collection period.
- For the next 24 hours, collect all your urine. Your doctor or lab will usually provide you with a large container that holds about 1 gal (4 L). The container has a small amount of preservative in it. Urinate into a small, clean container and then pour the urine into the large container. Do not touch the inside of the container with your fingers.
- Keep the large container in the refrigerator for the 24 hours.
- Empty your bladder for the final time at or just before the end of the 24-hour period. Add this urine to the large container and record the time.
- Do not get toilet paper, pubic hair, stool (feces), menstrual blood, or other foreign matter in the urine sample.
How It Feels
There is no pain while collecting a 24-hour urine sample.
There is no chance for problems while collecting a 24-hour urine sample.
A cortisol test is done to measure the level of the hormone cortisol in a 24-hour sample of urine.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Cortisol level in a 24-hour urine sample
Less than 100 micrograms (mcg) or less than 276 nanomoles (nmol)
5–55 mcg or 14–152 nmol
2–27 mcg or 5–75 nmol
- One cause of Cushing's syndrome is Cushing's disease, a condition caused by a noncancerous tumor of the pituitary gland (adenoma). An adenoma causes the pituitary gland to make too much of the hormone adrenocorticotropic hormone (ACTH), which in turn causes the adrenal glands to make too much cortisol.
- ACTH can be made by other conditions, such as cancer of the lung. This high ACTH level causes the adrenal glands to make more cortisol.
- The adrenal gland can develop tumors (benign or cancerous) that make cortisol and cause Cushing's syndrome.
- A high blood cortisol level can be caused by severe liver or kidney disease, depression, hyperthyroidism, or obesity.
- Conditions such as recent surgery, illness, injury, or whole body infection (sepsis) can cause high cortisol levels.