my son is 3year old his weight is 10.84 and he is not sleeping well every night he wakeup and cry,why this happens to him? how can I solve this problem?

A. Could be associated with hunger deficiency of iron in the body and your child is quite under weight so maybe it is just because of that also the child is being more cranky and not sleeping well you really need to make sure that your child is comfortably full before going to sleep and avoid giving daytime now so the child gets tired and sleep automatically early in the night