Why do muscles get achy and restless while you have a fever?

Question

Title. When I get a fever my muscles often feel achy and restless. What causes this?

In: 56

Answer 1

When you have a fever, your immune system jumps into action. This reaction causes an increased amount of white blood cells, which leads to inflammation and weakness – called myositis, and joint and muscle pain called – called myalgia. The protein that the body produces to kill the virus, not the virus itself, is what causes the majority of the symptoms you feel while you have an infection.