When the influenza virus enters the body, it triggers a response from the immune system that leads to inflammation. This process causes blood vessels to become leaky, allowing immune cells to travel to the site of infection and attack the virus. However, inflammation also affects the nerves in the body, making them more sensitive to pain.

This increased sensitivity is what makes muscle and joint aches feel more intense and uncomfortable during flu symptoms. The combination of inflammation and increased nerve sensitivity is what makes the flu feel so achy and miserable.

Understanding this relationship between inflammation and pain can inform treatment options for flu sufferers. Over-the-counter pain relievers that reduce inflammation can help alleviate some of the discomfort associated with muscle and joint aches. Additionally, knowledge of this relationship can inform the development of new treatments for flu that target both inflammation and nerve sensitivity directly.