"Have you not heard the little rhyme? "Don't talk about your indigestion, 'How are you" is a greeting not a question. I always answer "Fine thanks how are you?" If people are my friends or relatives and they really care they will ignore that and ask me privately "How are you really going though?" then I will tell them the truth. and because they are friends I know they will understand and not make any of those annoying responses. "