The case of infants sleeping with their tongues in the middle of two lips is considered a normal phenomenon, but it cannot be ruled out to be related to factors such as mouth ulcers and trisomy 21. The actual fact is that you can find a lot of people who are not able to get a good deal on a lot of things. If the infant is not accompanied by other abnormal symptoms, parents can not worry too much, as the infant grows up, the symptoms will ease on their own; 2, mouth ulcers: If ulcers appear in the mouth, may lead to pain in infants, can be manifested as sleeping tongue in the middle of the two lips to relieve pain, clinical advice to be treated with watermelon cream, rehabilitation new liquid and other drugs; 3, trisomy 21: mainly due to genetic factors The infant may have a special face, which may show symptoms such as sleeping with the tongue in the middle of the lips, more saliva, small and round head, short and wide neck, etc. Later, there will be low intelligence. It is recommended to visit the hospital for genetic examination to make a clear diagnosis, and parents are required to educate and train patiently at a later stage, which helps to exercise the infant’s self-care ability.