The flu, short for influenza, is a contagious respiratory illness caused by influenza viruses. It affects the nose, throat, and sometimes the lungs, leading to a range of symptoms that can vary in severity. Common symptoms include fever, chills, muscle aches, cough, congestion, runny nose, headaches, and fatigue. The flu can lead to serious complications, particularly in vulnerable populations such as young children, the elderly, pregnant women, and those with underlying health conditions.
The flu virus spreads primarily through respiratory droplets when an infected person coughs, sneezes, or talks. It can also be transmitted by touching surfaces contaminated with the virus and then touching one's face. Vaccination is the most effective way to prevent the flu, and the vaccine is typically updated annually to provide protection against the most common circulating strains. In addition to vaccination, practicing good hygiene, such as frequent handwashing and respiratory etiquette, can help minimize the risk of infection.