Adrenal insufficiency is a rare, potentially life-threatening condition whose diagnosis requires a high index of suspicion. Adrenal insufficiency may be primary, secondary, or tertiary with varied etiologies. Primary insufficiency may be part of a cluster of autoimmune diseases, referred to as autoimmune polyglandular syndrome(s) (APS). We describe a case of a 15-year-old male who presents to a local emergency department complaining of fatigue, fever, abdominal pain, nausea, and vomiting for a few days with a preceding viral illness. The patient was hyponatremic and hyperkalemic with skin hyperpigmentation, raising concern for adrenal insufficiency. Laboratory workup confirmed autoimmune primary adrenal insufficiency, with subsequent laboratory studies revealing autoimmune thyroiditis and celiac disease. Concomitant Addison's and Hashimoto's diseases led to a diagnosis of APS type 2. The patient was started on steroid replacement with rapid clinical improvement.