Hyperthyroidism may cause generalized swelling as well as localized swelling such as goiter and swelling of the lower extremities. The main causes of swelling include hypoproteinemia, thyrotoxic heart disease, and so on. Different patients have different manifestations, it is recommended to go to the regular hospital for treatment. 1. Hypoproteinemia: hyperthyroidism is a disease characterized by high metabolic state, if the condition is not properly controlled for a long time, it will cause hypoproteinemia due to the excessive consumption of protein in the body, which can be manifested as generalized swelling, pleural effusion, peritoneal effusion and other symptoms. 2. Thyrotoxic heart disease: it can be manifested as atrial fibrillation, heart failure, generalized swelling is often symmetrical, starting from the ankles and gradually rising to involve the calves, thighs, abdomen and so on. It is recommended that patients with hyperthyroidism or generalized swelling consult a doctor in time to avoid delaying treatment.