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
Dec 19, 2025 · Flu, also called influenza, is an infection of the nose, throat and lungs, which are part of the respiratory system. The …
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 …
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 …
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 …
Influenza: Causes, Symptoms, Diagnosis, and Treatment
Sep 9, 2025 · Influenza is a contagious respiratory illness caused by influenza viruses. Unlike the common cold, which can be …
National Flu Activity Map - Flustar.com
1 day ago · A resulting 12-point cold & flu severity index is further broken out into five levels, helping to paint a regional and national …
Site Index | Influenza (Flu) | CDC
Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs.
Signs and Symptoms of Flu | Influenza (Flu) | CDC
Aug 26, 2024 · Learn about identifying flu symptoms, how the diagnosis works, common complications, and more.