What type of infection is influenza?

Influenza is classified as an acute contagious respiratory infection, which accurately describes its nature and transmission. It is caused by influenza viruses that primarily affect the upper respiratory tract, leading to symptoms such as fever, cough, sore throat, and muscle aches. The term "acute" indicates that the illness comes on suddenly and is typically of short duration, while "contagious" highlights its ease of spreading from person to person through respiratory droplets when an infected person talks, sneezes, or coughs. The respiratory system is predominantly impacted, distinguishing it from other types of infections that may affect different bodily systems.