Heart rate refers to the number of heartbeats per minute in a normal person in a quiet state, also called quiet heart rate, generally 60-100 beats per minute, which can vary individually depending on age, gender or other physiological factors. Generally speaking, the younger you are, the faster your heart rate is, the slower your heart rate is in older people than in younger people, and the faster your heart rate is in women than in men of the same age, all of which are normal physiological phenomena. In a quiet state, the normal heart rate for adults is 60-100 beats per minute, and the ideal heart rate should be 55-70 beats per minute (athletes have a slower heart rate than the average adult, usually about 50 beats per minute). Heart rate variability is closely related to heart disease. In adults, a heart rate of more than 100 beats per minute at quiet (usually not more than 160 beats per minute) is called sinus tachycardia, which is commonly seen after excitement, agitation, smoking, alcohol, strong tea or coffee, or in pathological states such as infection, fever, shock, anemia, hypoxia, hyperthyroidism, heart failure, or after the application of drugs such as atropine, epinephrine, ephedrine, etc. In adults, a heart rate of less than 60 beats per minute at quiet (usually above 45 beats per minute) is called sinus bradycardia, which can be seen in healthy people and athletes who have been engaged in heavy physical work for a long time; or in hypothyroidism, increased intracranial pressure, obstructive jaundice, and overdose of digitalis, quinidine, or benzos. If the heart rate is below 40 beats per minute, a condition such as pathological sinus node syndrome or atrioventricular block should be considered. Atrial fibrillation should be considered if the pulse is unequal in strength and irregularity and the pulse rate is less than the heart rate. If the heart rate is more than 160 beats/minute or less than 40 beats/minute, it is mostly seen in patients with heart disease, and if it is often accompanied by palpitations, chest tightness and other discomfort, early detailed examination should be performed so that the cause can be treated.