Diffuse thyroid lesion is a pathological change that may be associated with Hashimoto’s thyroiditis, Graves’ disease, etc. Diffuse thyroid lesion caused by Graves’ disease may affect the heart when the condition is serious and prompt medical attention is recommended. When abnormal thyroid hormone secretion occurs, it may affect the heart. If the thyroid gland secretes too much, it may cause thyroid crisis, with clinical manifestations such as high fever, profuse sweating, tachycardia, irritability, anxiety, delirium, nausea, vomiting, diarrhea, and in severe cases, heart failure, shock and coma. If the thyroid gland secretes too little, resulting in the body’s metabolic rate is reduced, typical manifestations such as fear of cold, feeling of swelling in the hands and feet, constipation, drowsiness, memory loss. Involvement of the heart can also lead to pericardial effusion, causing heart failure. If the patient’s examination reveals diffuse thyroid lesions, it is recommended to go to the hospital in time for consultation, identify the cause of the disease, and then treat the symptoms.