Bradycardia that occurs in normal healthy people, athletes and during sleep is generally not harmful to the body, mostly asymptomatic, and is a normal physiological state, so there is no need to be nervous. But intracranial diseases, severe hypoxia, hypothermia, hypothyroidism, obstructive jaundice and vasovagal syncope and other diseases and drugs caused by bradycardia need to be paid attention to, serious bradycardia can cause insufficient blood supply to the heart, brain and other important organs, there is the possibility of sudden death.