Four-month-old baby shaking his head while sleeping usually attracts the attention of parents, as parents do not have to worry too much, may be a normal phenomenon, may also be due to eczema or baby rickets caused by. 1, the normal phenomenon: baby first sleep shaking head for the normal phenomenon, because shaking head is the baby in the subconscious sleep will appear symptoms. As the baby sleep gradually deepen, the symptoms of shaking head will gradually disappear. So the baby sleep shaking head symptoms, parents are advised to observe whether it is the first sleep period or mature sleep period. Then there is the ambient temperature and humidity is not appropriate will also make the baby sleep restless, manifested as shaking head. 2, eczema: small babies with delicate skin, allergies, external stimuli, etc. can cause the occurrence of head and facial eczema, eczema will generally be more itchy, the baby will also be uncomfortable due to the performance of shaking his head. You can observe whether the baby’s head eczema, if it is due to eczema caused by sleeping shaking head, it is recommended to go to the hospital in a timely manner. 3, rickets: due to the lack of vitamin D leads to baby calcium and phosphorus metabolism disorder, there will be increased neuroexcitability performance, is also a common cause of baby sleep shaking head phenomenon. It is recommended that parents follow the doctor’s instructions to give their babies regular oral vitamin D. When the weather is good, you should also take your baby outdoors and get more sunlight. Shaking head at bedtime is usually caused by the above reasons. As parents, take appropriate treatment according to the cause.