Normal heart rate ranges from 60 to 100 beats per minute, regardless of day and night. A heart rate of less than 60 beats per minute is considered bradycardia, while a heart rate of more than 100 beats per minute is considered tachycardia. Bradycardia has two kinds of physiological and pathological conditions, physiological conditions are long seen in long years engaged in sports, or heavy physical labor groups, some people’s heart rate will be lower than 60 beats per minute, but without any clinical manifestations and energetic, it is not pathological; pathological bradycardia is mostly a variety of conduction block caused by cardiac arrhythmia, we should do the relevant examination to confirm the diagnosis and then targeted treatment. Tachycardia is also divided into physiological and pathological, physiological tachycardia is common after emotional excitement, a lot of smoking, drinking, after sufficient rest and change the bad work and rest can be relieved by themselves; pathological tachycardia may be associated with a variety of infections, hyperthyroidism, severe pain, severe anemia, heart failure, etc., and need to do the relevant tests to confirm the diagnosis and treatment.