What do you mean large?

There is a condition called megalocephaly which literally means, 'enlarged head'.

I don't know the details but it was a term I memorized for medical terminology and what I remember now is that you need to get it checked out by a doctor. It could be bad and it might not be. It all depends on the person's body and how that body deals with it.

So please, consult a doctor (even a Physician if it's not a child. For children, a Pediatrician).