A rhythm paced by the sinus node, which is the pacing point of the normal heart, is called sinus rhythm, and is considered sinus tachycardia when it occurs at a frequency greater than 100 beats per minute. Sinus tachycardia is mostly caused by physiological factors or other diseases, and can be improved after eliminating the cause and treating the original disease. Most sinus tachycardia is caused by physiological factors, such as stress, anxiety, exercise or drinking coffee, strong tea or too much alcohol. Some non-cardiac diseases such as fever, anemia, and hyperthyroidism can also cause sinus tachycardia. In addition, primary cardiac diseases such as myocarditis and pericardial effusion can also cause sinus tachycardia. Sinus tachycardia caused by physiological factors has no specific symptoms. Sinus tachycardia caused by various diseases, in addition to the symptoms of the original disease, symptoms such as panic, fatigue, and decreased exercise tolerance are more common. The diagnosis of sinus tachycardia requires electrocardiogram and ambulatory electrocardiogram. For patients who still have symptoms after controlling the cause and eliminating the trigger, β-blockers or calcium channel antagonists can be considered for treatment. In summary, sinus tachycardia is a sinus arrhythmia with a frequency of more than 100 beats per minute. The etiology is both physiological and disease factors, which need to be further clarified by electrocardiogram and other examinations before treatment.