The normal adult heart rate in a quiet state is 60-100 beats per minute, with an average heart rate of 75 beats, and the majority of normal individuals should have a resting heart rate between 55-90 beats per minute. In the same body, the heart rate is slower during quiet or sleep, while the heart rate can be reactively accelerated during exercise or emotional excitement. In general, athletes or people who exercise regularly can have a faster heart rate at rest than normal adults due to their higher heart rate reserve capacity. If the heart rate is too fast or too slow, it is easy to have panic, chest tightness, breathlessness and other uncomfortable symptoms. It is important to pay attention to more rest, develop good habits and protect the heart, which can reduce the occurrence of myocardial infarction, acute coronary syndrome, cardiovascular disease, heart failure and other diseases. If the heart rate is too slow, below 40 beats per minute, be alert to the risk of cardiac arrest. Therefore, it is important to observe the change of heart rate in general.