Is influenza A severe?

Infection with H1N1 influenza is relatively serious. First, H1N1 is contagious, so individuals who become infected need to self-isolate. Additionally, the range of symptoms associated with H1N1—such as persistent fever, chills, muscle and joint pain, headache, fatigue, loss of appetite, sore throat, dry cough, nasal congestion, and runny nose—can cause significant discomfort. If the condition is not properly controlled, complications such as pneumonia, myocarditis, and encephalitis may develop, which in severe cases can even lead to death.