When there is an abnormality in the thyroid gland, such as hyperthyroidism, it may cause a fast heartbeat. However, a fast heartbeat is not necessarily triggered by thyroid problems, but may also be caused by emotional excitement, or coronary heart disease, hypokalemia and other diseases, which need to be further examined. 1, physiological factors: when the human body is in a state of excessive excitement, it will cause increased sympathetic excitability and adrenaline secretion, which will cause the human body to have a rapid heart rate, sweating, fast breathing and other phenomena. 2, hyperthyroidism: the thyroid gland produces too much thyroid hormone will cause the body’s basal metabolic rate to increase, which will cause the patient to experience rapid heartbeat, panic, loss of weight, sweating, hand tremors and other symptoms. 3, coronary heart disease: coronary heart disease people because of coronary artery occlusion to some extent, resulting in poor blood circulation, triggering myocardial ischemia, necrosis and other phenomena. In serious cases, there will be chest tightness, panic, increased heart rate, chest pain, dyspnea and other manifestations. 4、Hyperkalemia: serum potassium ions are too low to maintain the normal function of nerve and muscle cells, and patients will experience symptoms such as dyspnea, increased heart rate and atrial fibrillation. Fast heart rate suggests seeking medical treatment in time to make a clear diagnosis, so as not to lead to further aggravation of the condition.