Response given when the action itself seems as if it either hurt like the dickens, or was extremely embarrassing.
BJ tried to clear the railing and smacked face first into the concrete next to the stairs. He then jumped up and sputtered out "I'm OK!" while dribbling blood.
John stumbles over a wet floor sign at the mall, jumps up and shouts out "I'm OK!" Meanwhile, Susie looks at him, and thinks he's a twat.