Babies sleeping with their mouths open need to take corrective measures according to the situation. If colds cause nasal congestion, need physiological sea salt water rinsing, anti-cold medication; such as adenoid hypertrophy, according to the blockage of the nasal cavity, medication, surgical treatment. 1. Cold, if the baby has recently caught a cold, nasal mucosa edema, increased secretions, blocking the nasal cavity. You can use physiological sea salt water to rinse the nasal cavity, follow the doctor’s instructions to use anti-cold medication, such as pediatric cold and flu granules. 2. Adenoid hypertrophy, mostly due to repeated upper respiratory tract infections caused by adenoid inflammation and hyperplasia, blocking the nasal cavity after the breathing is not smooth, open-mouth breathing, adenoid face. If the blockage of the nasal cavity is small, consider the combination of bacterial infection can be treated with antibacterial drugs such as cefixime according to medical advice. If the blockage area is larger than 2/3, surgery is recommended. Babies sleep with their mouths open, try to go to the hospital to find out the cause and timely treatment, to avoid affecting the child’s sleep quality.