A normal person has about one million heartbeats per day. Number of heartbeats: A normal adult's heartbeat should be between 60-100 beats per minute. More than 100 beats/minute is called tachycardia, slower than 60 beats/minute is called bradycardia. The most common causes of tachycardia are fever, exercise, emotional stress, anemia and other extracardiac causes. If the cause of tachycardia is not related to any of the above, the heart itself should be considered as a disease, most commonly myocarditis and hyperthyroidism. Bradycardia is most common in the elderly. If the number of heartbeats suddenly slows down, it must be related to the heart and may be a danger sign. Heart rate is the number of heart beats per unit of time. It generally refers to the number of heartbeats per minute. There is significant individual variation in the heart rate of normal adults at rest, which averages around 75 beats per minute (between 60 and 100 beats per minute). Heart rate can vary according to age, sex, and other physiologic conditions. In newborns, the heart rate is rapid, up to 130 beats/minute or more. In adults, the heart rate of women is generally slightly faster than that of men. In the same person, the heart rate slows down during quiet or sleep, speeds up during exercise or emotional excitement, and speeds up or slows down under the influence of certain drugs or neurohumoral factors. Regular physical labor and physical exercise people, usually slower heart rate.