Constant itching & scratching

For as long as I can remember I've been a scratcher. I mainly scratch my head and neck but it's not necessarily limited to that. And no, it's not dandruff or anything like that.
I think it's a compulsive thing. My family used to tell me I did it all the time and it drove them nuts, and my husband tells me I even do it in my sleep.
It's like whatever's happening inside my brain manifests on the outside of my head.
Does anyone else do this??

Hi, tamarah! Do you do it out of stress? Have you talked to a psych or a doctor?