One year old baby side sleep is normal, but can not let the baby long-term side sleep in one direction. Baby sleep side sleep, flat sleep are normal phenomenon, but can not let the baby sleep, long-term side sleep in the same direction, the baby is still in the developmental stage of the skull, face, long time to keep side sleep in one direction, easy to squeeze one side of the cranium, may lead to the baby’s head shape, face shape abnormality. Therefore, parents should pay attention to the sleeping position of the baby, if the baby is in the same direction for a long time, help the baby to turn over and turn his/her face to the other side. If your baby has any physical discomfort or abnormalities, you should go to the hospital in time to avoid delaying the condition and causing more serious consequences.