When the influenza virus enters the body, it triggers the immune system to produce a flood of inflammatory chemicals. These chemicals cause blood vessels to become leaky, allowing immune cells to travel to the site of infection and attack the virus. This process also leads to the characteristic flu symptoms, including muscle and joint aches.
Inflammation also affects the nerves in the body, causing them to become more sensitive to pain. This can make the muscle and joint aches feel more intense and uncomfortable. The combination of inflammation and increased nerve sensitivity is what makes the flu feel so achy and miserable.
Understanding how inflammation contributes to flu symptoms can help explain why over-the-counter pain relievers, which reduce inflammation, can help alleviate some of the discomfort. Additionally, this knowledge can inform the development of new treatments for the flu that specifically target the inflammatory response itself.