This study intends to conduct a retrospective and prospective study on children with hyperthyroidism, and it is a non-intervention study to collect information on diagnosis and treatment and long-term follow-up of children with hyperthyroidism. To investigate the clinical characteristics, treatment effect, side effects and remission of hyperthyroidism in children, to analyze the predictive factors for the effect of antithyroid drug treatment, remission and recurrence after drug withdrawal, and to explore the risk factors related to the occurrence of antithyroid drug-related adverse reactions.