The baby sleep has been swinging his head from side to side may be sweating, head itching and lack of vitamin D, calcium and other reasons. 1. Sweating: if the indoor temperature is too high or the baby is wearing too thick and cover too thick and so on, resulting in the baby sweating more, due to the stimulation of sweat, the baby’s head is uncomfortable, will be swinging his head; usually do not give the baby to wear too thick or cover too thick, the indoor temperature should also be appropriate. 2. Itchy head: If the baby comes into contact with substances that can easily lead to allergies, such as dust mites, leading to allergies in the baby’s head, itchy symptoms, due to the baby’s discomfort, will also swing the head from side to side; 3. lack of vitamin D or calcium: if the baby’s body lacks vitamin D, calcium will make the nerve excitability increase, resulting in sleep disturbance, will also appear always bobbing head phenomenon. The baby sleeps always swinging his head from side to side, it is recommended to go to the relevant departments of the regular hospital for consultation and clear diagnosis.