Can antibiotics be bad?

Yes, absolutely: Most of the time, appropriate use of antibiotic can be quite useful and save lives, but severe or even fatal allergic/ reaction can occur--rare but quite scarry is called steven-johnson syndrome (severe rash involving even the inside of mouth/eyes etc...This cause severe skin peeling, thus fluid loss and infections are significant concerns. So, use any med only if need to. Consult doc. Good luck.

Yes... they can be.: They can be bad if used inappropriately or if one has an allergic reaction to them.

No, if used properly: Antibiotics are excellent in treating infections! visit a physician when you think you have an infection (fever, chills, abscesses) - only certain antibiotics treat certain bacteria, your doc might run some tests before they give you an rx. Do not try to self treat with antibiotics: it can be dangerous to you and it can induce resistance from the bacteria if you take it unnecessarily.