Definition
The flu is a contagious infection of the nose, throat, and lungs caused by the infuenza virus.Symptoms
The flu usually begins abruptly, with a fever between 102 and 106 °F. (An adult typically has a lower fever than a child.) The fever usually lasts for a day or two, but can last 5 days.Other common symptoms include:
- Body aches
- Chills
- Dizziness
- Flushed face
- Headache
- Lack of energy
- Nausea
- Vomiting
The most prominent of the respiratory symptoms is usually a dry, hacking cough. Most people also develop a sore throat and headache. Runny nose (nasal discharge) and sneezing are common.
These symptoms (except the cough) usually disappear within 4 - 7 days. Sometimes, the fever returns. The cough and tiredness usually last for weeks after the rest of the illness is over.
Other symptoms may include:
- Loss of appetite
- Muscle Aches and stiffness
- Stuffy, congested nose
- Sweating
- Worsening of underlying illness, such as asthma or heat failure