The hazards of sleeping with your mouth open include: pharyngeal discomfort, sleep apnea syndrome, and adenoid facies in children. 1. Pharyngeal discomfort: the nasal cavity has a moisturizing air, filtering effect, long time open mouth breathing will stimulate the pharynx, may feel dry, itchy, sore throat, and even lead to chronic inflammation and other discomforts. 2. Sleep Apnea Syndrome: Sleeping with the mouth open and breathing can easily lead to snoring and sleep apnea, resulting in lack of oxygen, mental depression, and increased risk of chronic diseases. 3. Children’s adenoid face: the common cause of children’s open-mouth breathing is adenoid hypertrophy, long-term open-mouth breathing will form a special face, the face becomes longer and narrower, the jaw shrinks back, and the reverse jaw, in addition, it may also affect the child’s development. If there is open mouth breathing during sleep for a long period of time, it is recommended to consult a doctor to clarify the cause, and if it is adenoid hypertrophy or other problems, it is necessary to have timely surgical treatment.