Four-month-old babies frequently shake their heads from side to side during sleep can be seen in vitamin D deficiency, skin diseases and other conditions, the intervention needs to be based on the cause. 1. Vitamin D deficiency: such as nutritional vitamin D deficiency rickets, in the early stage of the disease, mostly occurring within 6 months after birth, can appear in the sleep of sweat stimulation of the scalp and shaking the head, accompanied by irritability, annoyance, etc., some of the age of the baby can appear cranial bone softening, the need for a reasonable diet, under the guidance of the doctor to correctly supplement the vitamin D and so on. 2. Skin diseases: such as scalp eczema baby, can appear itchy and other obvious discomfort, the baby can appear in the sleep of the above symptoms, breastfeeding their mothers need to pay attention to the daily diet, and dermatology actively consult the doctor, the serious can be used under the guidance of the physician glucocorticosteroid (such as dinexed cream) and so on the treatment. 3. Other: If the indoor environment temperature is high, the baby is uncomfortable, may appear frequently shaking his head from side to side while sleeping, need to pay attention to the indoor temperature. All of the above medications should be used under the guidance of a physician, and it is recommended to actively seek medical attention and intervention by a specialist.