This may be a silly noob question, but I haven't been able to find anything about it by searching.

Those of us who take antihistamines (or "histamine blockers") know that they don't actually get rid of the histamine in our system. It just prevents our body from "seeing" the histamine, so to speak. So what then happens to the histamine, if it never reaches the receptors? Does anyone know?

I know there are substances that are supposed to break down histamine, such as DAO, but do they work the same way when the body doesn't know that the histamine even exists? Or does the histamine just collect and build up over time? I'm sure it has some sort of half-life, so that it eventually breaks down on its own, but I have to wonder if there might not be other consequences to having these histamines in our body over the long haul.