or the Flu, refers to illnesses caused by a number of
different influenza viruses. Flu can cause a range of
symptoms and effects, from mild to lethal.
strains of flu, seasonal flu and the
H1N1 (Swine) flu, are currently
circulating in the United States. A
third, highly lethal H5N1 (Bird) flu is
being closely tracked overseas.
healthy people recover from the flu
without problems, but certain people are
at high risk for serious complications.
efforts are underway to track and
monitor the spread of all flu viruses.
In the U.S., epidemiologists at the
Centers for Disease Control (CDC) are
working with states to collect, compile
and analyze reports of flu outbreaks.
More on the
current situation from the CDC.
symptoms may include fever,
coughing, sore throat, runny or stuffy
nose, headaches, body aches, chills and
fatigue. In H1N1 (Swine) flu infection,
vomiting and diarrhea may also occur.
outbreaks of the seasonal flu usually
occur during the late fall through early
spring. Most people have natural
immunity, and a seasonal flu vaccine is
available. In a typical year,
approximately 5 to 20 percent of the
population gets the seasonal flu and
approximately 36,000 flu-related deaths
Learn more in
OUR expanded section on the Flu ›