Evidence-based
Flu
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•Last Updated: November 20, 2025
“The flu” is a type of respiratory infection caused by influenza viruses. It has a lot in common with the common cold, but its symptoms tend to come on faster and be more severe. It isn’t typically serious, but it can be severe in newborns, older people, and people with immune issues.
Flu falls under the Immunity & Infectious Disease category.
