The reason why the heart is beating fast and cannot sleep: First, it may be due to strenuous exercise, excessive emotional excitement, drinking alcohol, strong coffee and tea, the sympathetic nerve overexcitation, which is a normal phenomenon. Second, may be the original heart disease patients, in lying down due to the return of blood, heart load increased, if accompanied by dyspnea, irritability, sweating, coughing up pink foam sputum, may be the occurrence of acute left heart failure. If a patient with a previous history of asthma has a rapid heartbeat accompanied by dyspnea and inter-throat croup, it may be an acute asthma attack. Fourth, it is possible that paroxysmal tachycardia has occurred. Therefore, if any of the above occurs, go to the hospital for further consultation and treatment.