Common causes of infant sighing include respiratory infections, indigestion, myocarditis, etc. It may also be the infant’s personal habitual sighing. 1. Respiratory infections: When infants have respiratory infections, they may have sighs due to varying degrees of obstruction of nasal ventilation, because sighing can improve ventilation. 2. Dyspepsia: bloating occurs during dyspepsia, which can also be characterized by long sighs, because sighing can relieve the discomfort caused by bloating, and the sighs will disappear after the bloating is relieved. 3. Myocarditis: Myocarditis caused by viral infection can also cause infants to sigh, because myocarditis when the child will feel tightness in the chest and shortness of breath, sighing to increase the inhalation of air, to relieve the discomfort. 4. Personal habits: Infants may sigh out of imitation and curiosity. There may be other reasons for the infant’s sighing, so it is advisable to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy.