The epiglottis is a small flap of tissue that hangs down from the back of the throat. It helps protect the airway during swallowing by preventing food or liquid from entering the trachea. The epiglottis can become infected or inflamed (epiglottitis) causing swelling. The swelling can block the airway and result in death. Airway blockage is more common in children. The bacteria Haemophilus influenzae is the most common cause of epiglottitis. Since childhood vaccination for Haemophilus influenzae became common the number of cases of epiglottitis has decreased.