Initial Blood Tests: These tests typically involve measuring baseline levels of cortisol, adrenocorticotropic hormone (ACTH), and key electrolytes like sodium and potassium. Additionally, autoantibodies associated with autoimmune Addison's disease are often screened for.

ACTH Stimulation Test: This diagnostic test assesses the adrenal glands' ability to produce cortisol. It involves measuring blood cortisol levels before and after the administration of synthetic ACTH, which normally stimulates cortisol production.

Insulin-Induced Hypoglycemia Test: This test is used to evaluate the pituitary-adrenal axis by observing the cortisol response to induced hypoglycemia. In healthy individuals, the stress of low blood glucose (triggered by insulin injection) should elicit a substantial increase in blood cortisol levels.