Symptoms of flu may vary from mild to severe. In occasional cases, it may lead to death. In most cases, the symptoms improve in a few days without complications. Symptoms of flu start after a short incubation period of one to four days. Incubation period is defined as the time from initial infection (after being exposed to an infected person) to the time that symptoms show up.
Symptoms of flu: Typically, the symptoms of flu start abruptly. Common symptoms of flu include:
General symptoms, such as fever, body pain, myalgia and headache start to decrease between day 2 and day 4 of the illness. After this period, respiratory symptoms may increase. Respiratory symptoms of flu include sore throat and cough. Most people develop a runny nose and sneezing. Nasal discharge is usually clear and watery. Most of these symptoms (except the cough) improve and resolve in a few days (4 - 7 days).
Most people begin to feel better within five to eight days, however, others may continue to have cough for a few more days and feel very tired for quite some time (may be for as long as two to three weeks). Recurrence of fever with increased cough may be due to the involvement of the lungs (i.e. development of pneumonia). Flu may make asthma or other breathing problems and other long-term illnesses worse.