Summary Autoimmune polyglandular syndrome (APS) type 2 is characterized by the presence of Addison’s disease (AD) along with autoimmune thyroid disease and/or type 1 diabetes. APS type 2 is known as Schmidt’s syndrome when autoimmune adrenal insufficiency is associated with chronic lymphocytic thyroiditis. We report a very rare case of a 28-year-old female patient who had Schmidt’s syndrome revealed by a thyroid storm (TS) concomitant with an acute adrenal crisis. The onset of AD resulted in a surgical emergency. The patient presented with cardiogenic shock and an acute abdomen. The precipitation factor was Hashitoxicosis presented as TS. This life-threatening condition was successfully reversed with aggressive medical therapy based on antithyroid drugs and intravenous glucocorticoids. This hyperthyroid phase lasted for a period of 8 months. The patient eventually developed hypothyroidism, suggesting that Hashimoto's thyroiditis was the most likely diagnosis. She was started on levothyroxine replacement therapy and remained euthyroid on levothyroxine. The case we describe had several diagnostic pitfalls that are discussed both at the start as well as during the evolution. Learning points Autoimmune diseases can appear concomitantly or succeed each other over time. The clinician must be vigilant to detect these diseases in time in order to avoid a misdiagnosis of a life-threatening emergency such as adrenal insufficiency or thyroid storm. Thyroid storm is an uncommon but life-threatening manifestation of hyperthyroidism. Diagnosis is dependent on clinical symptoms, and no specific laboratory tests are available. Glucocorticoids should be used in the treatment of thyroid storm because they have an inhibitory effect on peripheral conversion of T4 to T3. In patients who have severe thyrotoxicosis, especially in conjunction with hypotension, treatment with glucocorticoids has become standard practice because of the possibility of relative adrenal insufficiency or the possibility of undiagnosed Addison’s disease. The differential diagnosis of hyperthyroidism can be challenging. Graves’ disease can be discussed in view of the severity of the clinical presentation and the prolonged duration of the hyperthyroid phase. Hashitoxicosis is the initial hyperthyroid phase in chronic autoimmune thyroiditis. The hyperthyroid phase is always followed by definitive resolution, with persistent euthyroidism and no hyperthyroid relapses. Synthetic antithyroid drugs may be prescribed during the hyperthyroid phase of Hashimoto thyroiditis if the clinical presentation is severe and the duration of the hyperthyroid phase is prolonged.