antibiotic

An antibiotic is a medicine that fights bacteria — the tiny living things behind infections like strep throat, many ear infections, and some wound infections. It works by either killing the bacteria outright or stopping them from multiplying, so your body can mop up the rest.

Here's the catch worth remembering: antibiotics do nothing against viruses. A cold or the flu is caused by a virus, so an antibiotic won't help you feel better one day sooner — it just exposes you to side effects for no gain.

The first one was a happy accident. In 1928, Alexander Fleming noticed a mold had killed bacteria growing in his lab dish; that mold gave us penicillin. But there's a cost to overuse: every time we use antibiotics when we don't need them, the toughest bacteria survive and pass on their resistance — slowly creating infections our drugs can no longer beat.