Influenza (commonly called the flu) is a contagious respiratory illness caused by influenza viruses. It primarily affects the nose, throat, and lungs and can range from mild to severe illness. Influenza spreads mainly through droplets when an infected person coughs, sneezes, or talks.
Seasonal flu outbreaks occur every year and can impact people of all ages, but young children, older adults, pregnant women, and individuals with weakened immune systems are at higher risk of serious complications. While most people recover in a few days to two weeks, severe cases can lead to pneumonia, hospitalization, and even death.