Hyperthyroidism and hypothyroidism are both very harmful to the body and will have a great impact on the body if not treated properly. Therefore, both hyperthyroidism and hypothyroidism should be treated under the guidance of a doctor after diagnosis. The main danger of hyperthyroidism to the body is that it can lead to rapid heartbeat, arrhythmia, and in severe cases, heart failure. Hyperthyroidism can lead to increased eating and weight loss due to increased metabolism. In severe cases, hyperthyroidism can lead to high fever, rapid heart rate and other symptoms of hyperthyroidism. Hypothyroidism, when uncontrolled, can result in multiple plasma cavities throughout the body, slowing of the heart rate, and even leading to pericardial effusion and heart failure. Hyperthyroidism and hypothyroidism will cause great harm to the body, once found that hyperthyroidism or hypothyroidism should be timely to the regular hospital, under the guidance of the doctor standardized treatment.