Is 55 beats per minute normal?

The average person's heart beats 60-100 times per minute in a normal resting state. The speed of the heartbeat may change due to changes in weather, mood, emotions, stress, diet, etc. It may also be related to vagus nerve factors. A heart rate of 55 beats is basically normal. For example, athletes, due to regular exercise, have a stronger heart contraction ability. The amount of blood pumped by the heart with each beat increases, which is enough to meet the needs of various organs in the body. Therefore, a heart rate of 50-60 beats per minute is also normal.

This is normal, see the explanation below:

Heart rate: An adult's heart beats about 70 to 80 times per minute, and 60 to 100 beats is normal. Normally, if an adult's heart beats more than 100 times per minute when at rest, it is medically considered "tachycardia"; if it is less than 60 beats per minute, it is considered "bradycardia." The heart beats faster when working than when resting, women beat faster than men, children beat faster than adults, and newborns can beat up to 150 times per minute. On average, if a person lives to be 100 years old, his or her heart beats a total of about 4 billion times. Because athletes exercise regularly, their myocardial contractility is strong and the amount of blood returning to the heart during diastole is also large. Therefore, when athletes are at rest, a heart rate of less than 60 beats/minute is enough to ensure blood supply to the body. Some can reach 48-50 beats/minute. They have the ability and endurance to exercise.

There are several types of bradycardia, the most common of which is sinus bradycardia. Sinus bradycardia can be divided into pathological and physiological types. Physiological sinus bradycardia is a normal phenomenon. The general heart rate and pulse are 50 to 60 beats per minute. Athletes may have a heart rate of 40 beats per minute. No treatment is required. It is common in normal people during sleep and those who engage in more physical activities. A heart rate or pulse of less than 50 beats is mostly pathological and requires treatment. In severe cases, a pacemaker may be installed to speed up the heart rate. Sinus bradycardia is mainly caused by excessive vagal nerve tension: (1) Physiological: Normal people, especially those who participate in long-term physical exercise or heavy physical labor, may experience sinus bradycardia. Sleepiness and fear can also cause temporary bradycardia. For example, some techniques such as compressing the eyeball, pressing the carotid sinus, vomiting, and vasoinhibitory syncope can cause sinus bradycardia. (2) Drug-induced: β-blockers, reserpine, guanethidine, morphine, digitalis, quinidine, lidocaine, amiodarone, isoprenaline, neostigmine, anesthetics, etc. can cause sinus bradycardia. (3) Systemic diseases: hypothyroidism, obstructive jaundice, increased intracranial pressure,