Thinking of skipping the flu shot because you're worried about the side effects? Flu-shot side effects are uncommon and usually mild, including soreness or redness at the injection site, aches, and mild fever. A small number of people do have a more serious allergic reaction to the shot. And research suggests that roughly 1 out of every 1 million people vaccinated might develop Guillain-Barre syndrome, a neurological disorder. But the shot's protection against illness, hospitalization, and death far outweighs the risk. Still, if you've had Guillain-Barre syndrome, avoid the spray vaccine and discuss with your doctor whether to get a shot. Finally, there is no convincing evidence linking the mercury-containing preservative thimerosal with autism or other health problems. However, if you're concerned, ask for a preservative-free vaccine, such as Fluzone.

Read the top excuses for skipping the flu shot, take our quiz to test your flu smarts, and take a look at our Treatment Ratings (subscribers only) for flu remedies.