Influenza-like illness is a nonspecific respiratory illness characterized by fever, fatigue, cough, and other symptoms that stop within a few days. Most cases of ILI are caused not by influenza but by other viruses (e.g., rhinoviruses, coronaviruses, human respiratory syncytial virus, adenoviruses, and human parainfluenza viruses).
It’s important to know the difference between Flu or ILI and cold symptoms. A cold is a milder respiratory illness than the Flu or ILI. While cold symptoms can make you feel bad for a few days, flu symptoms can make you feel quite ill for a few days to weeks. The flu can also result in serious health problems such as pneumonia and hospitalizations.