Testing of blood Cortisol levels, is often used to help diagnose Cushing Syndrome and Addison's disease and can be used in conjunction with other tests to assess adrenal status.

As Cortisol decreases TSH, thereby decreasing thyroid hormone production, as well as inhibiting T4 to T3 conversion, measuring Cortisol is important and is now included in all Blue Horizon postal Thyroid Profiles.