If you experience any of the above symptoms, call your doctor. Sore throats, colds, and flu are caused by viruses, not bacteria, so taking antibiotics won't help. One exception is strep throat, which is caused by bacteria. A throat culture can determine what you have and whether it's best treated with antibiotics. Coughs and bronchitis are almost always caused by viruses.
Ear infections come in several types.
If your doctor doesn't recommend an antibiotic, don't ask for one. Sinus infections may be caused by bacteria or viruses. Antibiotics should only be used for severe infections, or ones that last more than two weeks, since those are more likely to be caused by bacteria. Adapted from information provided by the American Academy of Family Physicians, the American Academy of Pediatrics, the Alliance for the Prudent Use of Antibiotics, and the Centers for Disease Control and Prevention. N.W., Washington, D.C. 20009.