Most people recover from the flu in 7 to 14 days. However, adults with chronic diseases are at high risk for complications associated with influenza. The virus is sprayed into the air by an infected person through coughing and sneezing. Poor handwashing contributes to spreading the disease. Travel to other geographical areas where influenza is present can be a risk factor.
Pneumonia is the most serious complication.
It can be caused by the influenza virus itself, or due to secondary bacterial infection after the natural defenses of the lungs have been weakened by the flu. Reye Syndrome is a severe illness that can follow use of aspirin-containing products for viral infections. It tends to affect mostly children, and has been associated with influenza and chicken pox. You lower your risk of developing Reye Syndrome, which affects the liver and brain, by avoiding aspirin with a viral infection. This is a misleading term.