This article presents the case of an 81/2 year old girl who was admitted to hospital after exhibiting symptoms of weakness, vomiting and decreased levels of vigilance. The girl had suffered from shock of unknown origin that had required resuscitation 6 months earlier. At the time she had been diagnosed with hypothyroidism and was treated with thyroid hormones. Her first blood tests in our hospital indicated hyponatraemia, low blood sugar, compensatedmetabolic acidosis and considerably high TSH with normal peripheral hormones. Clinical findings were brown skin discoloration, low blood pressure, and weight stagnation after tremendous weight loss, which occurred during her first hospitalisation (6 months earlier). In this context, we made a tentative diagnosis of cortisol deficiency (Addison's disease) and a link with hypothyroidism was also suspected. In this paper, we demonstrate the diagnostic procedures for Schmidt's syndrome (APS type 2) and its therapeutic measures.