This page was reviewed or revised on Friday, October 14, 2011 1:47 PM
H1N1 flu virus is a strain of the influenza virus that usually affects pigs, but which may also make people sick. H1N1 flu virus is a respiratory illness that causes symptoms similar to those of the regular human seasonal flu.
Symptoms include headache, chills and cough followed by fever, loss of appetite, muscle aches and fatigue, runny nose, sneezing, watery eyes and throat irritation. Nausea, vomiting and diarrhea may occur in adults as well as in children. In more severe cases, or in people with chronic conditions, complications such as pneumonia may develop.
For more information on influenza - click here