The flu is caused by a virus. The
virus spreads through the air in droplets when someone who has the flu coughs, sneezes,
laughs, or talks. You can become infected when you inhale these viruses directly.
can also become infected when you touch a surface on which the droplets have landed
then transfer the germs to your eyes, nose, or mouth. Touching used tissues, or sharing
utensils, drinking glasses, or a toothbrush from an infected person can expose you
flu viruses, too.