How Do Doctors Diagnose Cushing Syndrome?

The doctor will go over your child’s health history and do a physical exam. They might also do screening tests to figure out if your child’s body is making high levels of cortisol.

Screening tests may include:

  • A 24-hour urine collection for cortisol measurements
  • Late-night saliva sample (11 p.m. to midnight) for cortisol measurement
  • Assessment of a morning (8 a.m.) cortisol level following administration of oral dexamethasone at 11 p.m. the previous night

If 2 out the 3 screening tests show high cortisol levels, the doctor will do more tests to figure out the cause of endogenous cortisol production, such as a pituitary tumor making an excess of ACTH (also called Cushing Disease), an adrenal tumor, or a tumor at a different site making too much of ACTH or a hormone that stimulates ACTH production (Ectopic Cushing Syndrome). These tests include:

  • An ACTH level
  • Imaging studies, such as an MRI or CT scan (to look at the pituitary gland, adrenal glands or other places for tumors)
  • Other tests that depend on the results of the previous tests

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Rev. 11/2019. MassGeneral Hospital for Children and Massachusetts General Hospital do not endorse any of the brands listed on this webpage. This webpage is intended to provide health information so that you can be better informed. It is not a substitute for medical advice and should not be used to treatment of any medical conditions.