Most people have a pulse rate of 60 to 90 beats per minute at rest. A pulse rate of 55 beats per minute may be a normal physiological phenomenon, but it may also be a pathologic bradycardia. 1. Normal physiological phenomenon: If an athlete or other people who have been engaged in heavy physical labor for a long time measure a pulse rate of 55 beats per minute when resting quietly and do not have other abnormal symptoms such as palpitations (rapid heartbeat, often accompanied by panic), then it is generally normal and does not require treatment. 2. Pathological bradycardia: a heart rate of 55 beats per minute may also be abnormal, such patients may suffer from myocardial ischemia, atrioventricular block and other cardiac diseases that can lead to pathological bradycardia, and the patient may also be accompanied by angina pectoris, chest tightness, fatigue and other abnormal symptoms. If the patient’s pulse rate remains below 60 beats per minute for a long period of time and is accompanied by abnormal symptoms, it is necessary to consult a doctor in a timely manner, and under the guidance of the doctor to improve the relevant examinations and then carry out targeted treatment and therapy, and do not delay the condition.