Hyperthyroidism can cause heart disease, and heart disease caused by hyperthyroidism is called hyperthyroid heart disease. Hyperthyroidism is a hypermetabolic syndrome caused by high concentrations of thyroid hormones in the blood due to various reasons. The main manifestations of hyperthyroidism are high metabolic symptoms such as overeating, easy hunger, panic, sweating, weight loss, and increased stool frequency. Excessive thyroid hormones acting on the heart can affect the heart rate and enhance the contractility of the heart muscle. Patients may experience panic and accelerated heart rate, resulting in increased systolic blood pressure, decreased diastolic blood pressure, increased pulse pressure, etc. It can also cause atrial fibrillation, premature atrial beats, premature ventricular beats and other arrhythmias. In severe cases, it can cause hyperthyroid heart disease such as heart enlargement and heart rate failure. Most patients with hyperthyroid heart disease can get better on their own after the hyperthyroidism is cured, but patients with long-term severe thyroid heart disease can be left with cardiac insufficiency.