Frequent head shaking may be caused by ear discomfort, vitamin D deficiency or eczema. 1. Ear discomfort: Cerumen or otitis media in the ears of infants may cause discomfort such as ear pain or dry itching, and infants will shake their heads to relieve the local discomfort. 2. Vitamin D deficiency: lack of vitamin D may lead to high nerve excitability, which may cause excessive sweating on the head of infants, and because excessive sweating may cause itching on the head, infants will shake their heads to alleviate head itching. 3. Eczema: If the baby’s head or neck suffers from eczema, it may lead to localized itching and discomfort, thus causing the baby to express discomfort by shaking his head frequently. If the baby shakes his head and does not see any relief, it is recommended to consult a doctor in a timely manner to clarify the cause of the disease, and then under the professional guidance of the doctor for treatment.