flu symptoms

The flu typically causes symptoms such as fever, chills, muscle aches, fatigue, and headaches. You may also experience a dry cough, sore throat, runny or stuffy nose, and sometimes nausea or diarrhea. These symptoms stem from your immune system fighting the virus, leading to inflammation and fluid buildup in the respiratory system. The feeling of exhaustion and body aches can be severe, making simple activities more difficult. Flu symptoms usually develop suddenly and can last a few days to a week or more, with some individuals experiencing lingering fatigue afterwards.