Swine flu, also known as H1N1, is a respiratory virus that causes flu-like symptoms in humans. The current H1N1 strain is contagious between people and has caused a potential global pandemic. Symptoms are similar to seasonal flu but can also include vomiting and diarrhea. The virus spreads through coughs and sneezes or touching contaminated surfaces. Proper hand washing and avoiding contact with sick individuals can help prevent spread of the virus. There is no vaccine yet for H1N1 but antiviral medications can help treat symptoms.