Whether or not a heart rate above 100 beats/min is dangerous depends on the magnitude of the heart rate elevation, the patient’s signs and the state in which he or she is. If the patient’s heart rate elevation is small and occurs less frequently, it has little effect on the body and may not be dangerous. A normal heart rate is a sinus rhythm, which generally fluctuates between 60-100 beats per minute. A heart rate higher than 100 beats/min is a large range change for both physiological and pathological reasons. If the heart rate is higher than 100 beats/min after insomnia, alcohol, strong tea, coffee or strenuous exercise, it may not be dangerous and usually recovers after removing the trigger. However, if the patient has coronary heart disease, hypertension and other underlying diseases, the appearance of a rapid heart rate, accompanied by panic, chest tightness, shortness of breath, dizziness, or even syncope, is very dangerous, and sudden cardiac death is likely to occur, which requires immediate consultation with the cardiology department. If the heart rate is slightly high under the stimulation of external factors, it usually does not require treatment and most of them are not dangerous and can be relieved by themselves. However, if the heart rate is higher than 100 beats per minute for a long period of time, you need to seek medical attention and have an electrocardiogram, cardiac ultrasound and other tests to determine the cause.