Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. Learn about flu, including symptoms, prevention methods, and treatment options.

Dec 19, 2025 · 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 the "stomach …

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 body aches, sore throat, fever and respiratory symptoms, which can be …

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, …

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 …

May 7, 2026 · Flu cases have reached a 25-year high in the US, driven by a mutated H3N2 subclade K strain. CDC data shows record doctor visits for flu symptoms. Experts warn immunity gaps are …

NHS information about flu, including symptoms, how to treat it yourself and when to get help.

6 days ago · For most people, flu stages evolve across five to seven days after symptoms appear. Here is a day-by-day guide to the flu and tips to boost your recovery.

Jan 16, 2026 · There are four types of the influenza virus (A, B, C and D) — influenza A and B cause seasonal epidemics every winter, per the CDC. The predominant strains that circulate in the U.S. are …