laughing so hard it hurts

When we say something is "hysterical" we usually mean that's a good thing. But sometimes, I think laughter can lead to hysteria in the sense of a loss of control. At least I think thats what happened to me last night. I was talking with my girlfriend Kylie, and I started laughing, until I was in pain, having trouble breathing, and yet being unable to stop. I'm not sure what that means.