Heart rate is the number of times the heart beats per minute in a quiet state. It can be calculated from a 3-minute average. Heart rate is the number of heart beats per minute, with the first heart sound as the starting point for measurement, in order to measure closer to the actual, the measurement time should be longer than one minute, it is best to measure about three minutes for the average. Normal adult heart rate is 60~100 beats per minute, slightly faster for women, more than 100 beats per minute for children under 3 years old, and slower for the elderly; adult sinus rhythm over 100 beats per minute is called sinus tachycardia, and sinus rhythm below 60 beats per minute is called sinus bradycardia. Heart rate measurement is one of the indicators of heart function and should be performed in a quiet environment. It is recommended to go to the hospital promptly if you have a fast or slow heart rate.