There's just one problem. While antibiotics are excellent at killing bacteria (as long as you match the right drug to the right germ), they're useless at killing viruses. And viruses, including the flu, cause 90% of respiratory infections. "Most upper respiratory infections are caused by viruses; a minority are caused by bacteria," says Lauri Hicks, MD, medical director of the Centers for Disease Control and Prevention's "Get Smart: Know When Antibiotics Work" program. For example, Dr. Hicks notes, only 2% of sinus infections are caused by bacteria and require an antibiotic.
So what, you say? Antibiotics might help and they certainly can't hurt, right? Wrong. The evidence is piling up that using antibiotics indiscriminately is dangerous from a public health standpoint (it can breed drug-resistant bacteria) and even personally (they kill off healthy bacteria in your body and may let toxic germs gain a foothold).
However, there are times when the icky green goo in your nose or the hideous rattling cough in your chest might benefit from the antibiotic superhero treatment. So how do you know if you need one?