Some people get very sick.
Each year, about 130,000 people go to a hospital with the flu, and 20,000 people die because of the flu and complications. The flu may cause fever, cough, sore throat, a runny or a stuffy nose, headache, muscle aches and tiredness. Some people describe the flu as being like the worst cold of their life. Most people feel better after 1 or 2 weeks. But for some people, the flu leads to serious, even life-threatening diseases, like pneumonia.