Honey, did you take your baby for a checkup? It may be that the baby has a headache, and another reason is that the baby lacks calcium. The baby is two and a half years old and can express something by himself. Adults can ask the baby why. The best way is to take the baby to check. When children's growth and development is critical, find out the reasons when problems are found.

I hope my answer is helpful to you. I'm Ziyue's mother, a preschool teacher. I wish the baby a healthy growth!