Although most people are ill for only a few days, some people have a much more serious illness, such as pneumonia, and may need to be hospitalized. Thousands of people die each year in the United States from the flu or related complications. Symptoms can occur within 1 to 3 days after exposure to an infected person . Usually, a doctor will diagnose a case of the flu based on typical symptoms of fever, chills, headaches, cough and body aches. There are a variety of tests that can be used to detect influenza.
Viral culture is able to differentiate between strains of a specific virus.
The contagious period varies, but probably begins the day before symptoms appear and extends for a week. However, t he viruses that cause flu frequently change, so people who have been infected or given a flu shot in previous years may become infected with a new strain. Rest and liquids are usually adequate. Because recommendati ons for treatment with these antiviral drugs vary with age, their use should be discussed with the patient's physician. Coughs and sneezes should be covered or shielded to protect others.