Though millions of us are exposed to the flu each year, for some the illness is very mild, no more bothersome than a cold. Others have no symptoms at all, while some unfortunate people are completely miserable. Typically, a case of the flu starts abruptly with a fever and that achy, "I'm coming down with something" feeling. The fever is usually higher than that of other respiratory viruses, up to 104° or 105° F. Quickly following are achiness, fatigue, chills, cough, sore throat, runny nose, glassy eyes, and loss of appetite. A headache, conjunctivitis, stomach pain, nausea and vomiting and a croupy cough may also be present.
It isn't always possible to tell the flu from a bad cold, but, in general, flu sufferers are more miserable—and since the flu occurs in epidemics, many others in the community are often affected at the same time. Basically, if it looks, feels, and acts like the flu during flu season, it probably is. After about three to six days, symptoms get better, though the cough and fatigue can drag on for weeks.