Girlfriend troubles (20 character Y!A limit)?

Well not so much troubles, but whatever. So my girlfriend loves me, I know she does. But sometimes she's just so condescending and I guess 'mean' for lack of a better word. She puts me down without even realizing it, I don't believe she even means to do it. The thing is, there's only so much of that stuff I can take. She'll just say things that she knows will piss me off, and stuff that actually hurts me more than anything. Like I said, I know she loves me, but what can I do about this?