Sinus arrhythmia is technically a category of cardiac arrhythmia. An arrhythmia is an irregularity in the rhythm of the heart, but it can take many forms, such as faster, slower, or no longer beating. Sinus arrhythmias are the least severe, and most are physiological in nature. Everyone’s normal heartbeat is in sinus rhythm because it is controlled by the sinus node, so as long as it is normal, it should be in sinus rhythm. Why does sinus arrhythmia occur again? In fact, it is related to many young people who have thin thorax or unstable breathing, because the electrical activity of our heart flows to the body surface through the inside, so the thorax will affect the change of our resistance, which will affect the formation of the current signal. Generally speaking, sinus arrhythmias are physiological and do not have uncomfortable symptoms, not to mention the need for treatment.