(Adapted from the Centers for Disease Control and Prevention)
The flu is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness, and at times can lead to death. Every year in the United States, 5% to 20% of the population gets the flu, more than 200,000 people are hospitalized from flu complications, and approximately 36,000 people die from the flu. Some of the complications caused by the flu include bacterial pneumonia, dehydration, and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes. Children may get sinus problems and ear infections.
The flu spreads in respiratory droplets caused by coughing and sneezing. It usually spreads from person to person, though occasionally a person may become infected by touching something with a virus on it and then touching their mouth or nose. Adults may be able to infect others beginning one day before getting symptoms and up to seven days after getting sick. That means that you can give someone the flu before you know you're sick as well as while you are sick.
The single best way to prevent the flu, even in healthy people, is to get a flu vaccine each fall. However, you're not helpless when it comes to practicing certain good health habits that can prevent the flu:
Many people use the term 'stomach flu' to describe illnesses with nausea, vomiting, or diarrhea. These symptoms can be caused by many different viruses, bacteria, or even parasites. While vomiting, diarrhea, and being nauseous or 'sick to your stomach' can sometimes be related to the flu -- particularly in children -- these problems are rarely the main symptoms of influenza. The flu is a respiratory disease and not a stomach or intestinal disease.