Which is more serious, hyperthyroidism or diabetes, if judged by the damage to the body, diabetes is more serious. Because of prolonged diabetes, patients can develop many microvascular and macrovascular complications, for example, it can cause eye blindness, kidney failure, numbness in hands and feet, and even complications such as diabetic gangrene, heart attack and brain infarction. It can seriously affect the quality of life and even threaten the patient’s life, while hyperthyroidism does not cause serious complications. From the treatment point of view, diabetes can only be controlled by oral medication or insulin, while hyperthyroidism has a choice of treatment options, such as medication, radioactive iodine-131 treatment, and surgery. Hyperthyroidism can be completely cured by iodine-131 therapy or surgery, and some patients can also be cured by taking oral anti-hyperthyroid drugs. However, diabetes is a chronic disease that can only be controlled, and there is no cure.