Signs and symptoms of flu People who have the flu often feel some or all of these signs and symptoms: Fever* or feeling feverish/chills Cough Sore throat Runny or stuffy nose Muscle or body aches Headaches Fatigue (very tired) Some people may have vomiting and diarrhea, though this is more common in children than adults. *It’s important to note that not everyone with flu will have a fever. How flu spreads Most experts believe that flu viruses spread mainly by droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are nearby. Less often, a person might also get flu by touching a surface or object that has flu virus on it and then touching their own mouth, eyes or possibly their nose.
Period of contagiousness You may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick. Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Some people, especially young children and people with weakened immune systems, might be able to infect others for an even longer time.” From CDC.gov http://www.cdc.gov/flu/keyfacts.htm