Hyperthyroidism is the abbreviation of hyperthyroidism. Apathetic hyperthyroidism is mainly characterized by marked emaciation, weakness, dizziness, fainting, neuroticism or apathy, diarrhea and anorexia. It can be accompanied by signs such as atrial fibrillation, muscle tremor and myopathy, and 70% of patients do not have goiter. Individual differences exist in the clinical manifestations of patients with apathetic hyperthyroidism. Indifferent hyperthyroidism is most common in elderly patients. The onset of the disease is insidious, the hypermetabolic symptoms are atypical, and the eye signs and goiter are not obvious. Clinically, patients are often misdiagnosed as malignant tumors due to obvious emaciation, and misdiagnosed as coronary heart disease due to atrial fibrillation. Therefore, this disease should be considered in the case of sudden and unexplained emaciation and new onset of atrial fibrillation in the elderly. Patients diagnosed with apathetic hyperthyroidism should actively cooperate with doctors for treatment.