polite way to respond to "are you feeling better today?"

I'm pretty open with my coworkers when I'm having a bad pain or energy day. As a therapist, I'm surrounded by people who are pretty good at reading body language, and generally can tell I'm feeling off. On occasion, I'll tell my clients I'm feeling poorly, as it isn't unusual for folks to assume my changed body language has something to do with them, and I don't want them to feel self conscious.

Often, the next day my coworkers they ask "how are you doing/are you feeling better today?" with the best intentions, and I never quite know how to answer. On one hand, saying no often leads to the look of sad/pity/you poor thing or requires an explanation that is longer than either of us is interested in. But saying "yes" is a flat out lie.

I definitely got some backlash in school of the "she's always complaining but she doesn't look sick" type, so maybe I'm more sensitive to this than most, but I think it is hard for people without chronic illness to understand that "feeling better" is relative and that there will be periods of days or weeks where I feel pretty uniformly lousy.

Have you come up with a polite way to honestly answer the question, without needing to go into more detail than you'd like to disclose?

I'd just say something like, "no not really, thanks for asking" or "much the same as yesterday, thanks for asking" and leave it at that. On the other hand maybe gumby has a point about not sharing in the first place if you don't want to be asked questions about how you're doing. I'm pretty private about my Crohn's 'cos it's just not something that 99% of people are going to get - they might understand the need to go to the toilet more often than the average person, but not the fatigue that usually accompanies it. And, in the end, where does moaning every day about how rubbish you're feeling get you anyway? We all need to vent sometimes, but I try to save venting for when I'm really feeling at the end of my tether.

I'm a bit more like you - I'm completely open with most people about my health. Maybe give them a number on a scale of 1-10? 1 being you're having an awesome day, 10 being you're in the hospital. That way, you can answer honestly, but then leave it up to them to ask more questions if they really want details. The nice thing with this is the scale is set on your own body's terms (what's 3 for us would be a 7 for healthy people), but you'll get fewer pity looks because they'll see your 3 as how they would put their own 3.

I'd be cautious around co-workers/bosses as it could be used against you.