The case patient has symptoms of Addisonıs disease, and the best test to confirm this diagnosis is an ACTH stimulation test. Random cortisol levels are not reliable tests for establishing the diagnosis because they can fluctuate throughout the day. Early morning levels of cortisol could give a good initial clue, but they would still need to be confirmed by an ACTH stimulation test. A dexamethasone suppression test is performed when Cushing’s syndrome is suspected, and insulin and C-peptide levels are tested when insulinoma is suspected.
