I have a condition that pretty much never surfaces on medicine, but sometimes does (no pattern I can tell). This happened the other night so I called out sick, just announcing I wasn't feeling well. It often passes within half the day.
I have awesome coworkers, friendly and supportive, and tomorrow they're sure to ask how I'm feeling, sometimes things like, e.g. "Did you catch the cold that's going around the office? Are you better now?"
I feel sketchy taking random single days off and never saying why. To them I feel like I seem to recover 100% by the next day, apparently after being too sick to log on even remotely. (Working from home is common and acceptable.) I'm also not a natural conversationalist so my responses don't help. ("Yup, better.")
In the past I've used excuses like "food poisoning." Or, I've pretended to actually be a little sick the next day. Obviously it's not my first choice to lie, but it's to keep my privacy while not raising suspicion, and to not make well-meaning coworkers feel weird for asking.
Are there any more tactful approaches I can take that's worked for anyone else? Or maybe just, a more acceptable lie I'd feel less guilty about?