**NOTE: All laboratory testing requires an authorizing physician in order to complete the laboratory testing**
A cortisol test may be used to help diagnose Cushing syndrome, or to help diagnose adrenal insufficiency or Addison disease, conditions associated with deficient cortisol. Cortisol is a hormone that plays a part in the metabolism of proteins, lipids, and carbohydrates, among other functions. Normally, the level of cortisol in the blood fluctuates throughout the day.