The flu is hard to diagnose because there are several other diseases that resemble it. You may have the flu if you have 1 or more of these symptoms: Fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills, fatigue and sometimes, with 2009 H1N1 flu, diarrhea and vomiting.
Most people with 2009 H1N1 flu have had mild illness and have not needed medical care or antiviral drugs; the same holds true for seasonal flu. To know for certain if you have the flu, a specific test would need to be performed. However, most people with flu symptoms do not need a test for the 2009 H1N1 flu because the test results usually do not change how you are treated.
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