My nephew who is 5 years old has been complaining of headaches. sometimes headache is followed by vomiting. is it migraine?

Headaches: Headaches and vomiting in a5year old may be more than migraine you nephew should be evaluated by a neurologist as soon as possible.

Possible: It is certainly possible that these are migraines. About 3-4% of children his age have migraine headaches. However, it is always best to have him evaluated by his doctor to make sure there isn't another cause for his headaches.