Hyperthyroidism (referred to as hyperthyroidism), mostly seen in young and middle-aged women, has typical symptoms such as agitation, talkativeness, fear of heat, goiter, hyperphagia, protruding eyes, and tachycardia. In recent years, it has been found that many elderly people suffer from hyperthyroidism; however, elderly patients lack the above typical symptoms, so they are easily misdiagnosed. Hyperthyroidism in the elderly is more common in the cardiac type and is easily complicated by organic heart disease. However, there is rarely tachycardia, but a variety of arrhythmias such as atrial flutter and atrial fibrillation; symptoms of heart failure may also be presented; some manifest as frequent angina pectoris and even myocardial infarction. One of the causes is the action of a large amount of thyroxine, which increases the load on the heart. The above symptoms are very much like coronary heart disease. Some patients present with anorexia, nausea, vomiting, diarrhea, and wasting, much like the symptoms of digestive tract cancer. A few patients exhibit neurological symptoms such as apathy, double vision, unresponsiveness, and drowsiness. Sometimes even coma. Therefore, elderly patients with hyperthyroidism are often misdiagnosed as heart disease, stomach cancer and digestive tract diseases. It is difficult to diagnose elderly hyperthyroidism by relying on atypical symptoms. Therefore, it is important to be vigilant and go to the hospital promptly if you have the above mentioned symptoms, as long as thyroid function tests are performed, the diagnosis is not difficult. If the diagnosis is clear, the patient should take reasonable anti-thyroid medication, usually not less than one and a half years, and should still go to the hospital often for detailed examination, especially heart examination, to find out whether there is a combination of coronary heart disease, a common disease in the elderly.