Influenza (Flu) | CDC
Flu is a contagious respiratory illness that infect the nose, throat, and sometimes the lungs. Learn about the current flu season and …
Influenza - Wikipedia
Influenza A virus and influenza B virus circulate in humans and cause seasonal epidemics, and influenza C virus causes a mild …
Influenza (flu) - Symptoms and causes - Mayo Clinic
Aug 29, 2026 · Flu, also called influenza, is an infection of the nose, throat and lungs, which are part of the respiratory system. The …
Flu (Influenza): Causes, Symptoms, Types & Treatment
Oct 11, 2022 · What is the flu (influenza)? The flu is an illness you get from the influenza virus. It causes symptoms like head and …
About Influenza | Influenza (Flu) | CDC
Feb 26, 2026 · Flu can cause mild to severe illness. Some people are at higher risk for more serious flu illness. Getting a flu vaccine …
Influenza | Definition, Symptoms, Treatment, & Prevention | Britannica
Sep 26, 2026 · Influenza is an acute viral infection of the upper or lower respiratory tract, marked by fever, chills, and a generalized …
Influenza (seasonal) - World Health Organization (WHO)
Feb 28, 2025 · Seasonal influenza (the flu) is an acute respiratory infection caused by influenza viruses. It is common in all parts of …
Flu (Influenza) - NFID
Influenza, commonly called flu, is a disease caused by a group of viruses that infect the nose, throat, and lungs. Many people have …
Flu (influenza) – influenza A and B, symptoms, vaccine | healthdirect
Influenza (the flu) is a viral infection that causes fever and chills, sneezing, coughing and a sore throat. The flu can be serious for …
Influenza - Infectious Disease - Merck Manual Professional Edition
Influenza is a viral illness caused by influenza viruses. It most commonly leads to fever, coryza, cough, headache, and malaise.