Learn about flu, including symptoms, prevention methods, and treatment options.

Dec 19, 2025 · Overview Flu, also called influenza, is an infection of the nose, throat and lungs, which are part of the respiratory system. The flu is caused by a virus. Influenza viruses are different from …

Aug 26, 2024 · Learn about identifying flu symptoms, how the diagnosis works, common complications, and more.

Influenza, commonly known as the flu, is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, …

Oct 11, 2022 · The flu is a common illness you get from the influenza virus. You’re at risk for serious complications if you have an underlying health condition or are pregnant.

Jan 16, 2026 · A mutated strain of influenza A, H3N2 subclade K, is surging worldwide, sparking concern about a severe flu season in the U.S. Here's what to symptoms to look out for.

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 picture of influenza activity in the US. The map also provides breakouts …

Sep 9, 2025 · Influenza Vaccination The flu vaccine is updated annually to match the most likely circulating strains. Available in injectable or nasal spray forms, it is recommended for nearly …

Jan 16, 2026 · Flu cases and hospitalizations are surging, already breaking last season's records. Here's where activity is highest, what symptoms to watch for and how to protect yourself.

Jan 22, 2025 · Influenza A and influenza B are the main strains of flu virus. Type A causes more cases, more severe illness and infects many species. Type B only infects humans.