Sometimes we say something and immediately realize our mistake, but sometimes we don't realize the damage caused by our question. So, I present to you ....
Unintentionally rude questions to quit asking people:
1- "Did you lose weight?"
You're trying to be kind, we get it. But some people hear this as, "you used to be super fat." So instead of questioning the weight loss, just say, "you look great!"
2- "Are you tired and/or sick?"
You're asking out of concern, but that concern is sparked by that individual looking a kind of like shit. So, just keep your question to yourself unless they start sneezing or coughing up a storm.