It’s impossible to know the root cause of this disease, but here is a factor that can be engaged with good natural medicine to reverse it:
Multiple chronic infections that cause chronic “Flulike” muscle aches from immune cytokine activation. In other words just as your muscles ache when you have the flu, they ache from chronic infections that come and never go away. This can include undiagnosed Lyme disease and many other infections, viral, bacterial, parasitic, etc.
For more information about Fibromyalgia from a Traditional Naturopath in Prescott AZ visit https://www.nhsofarizona.com/health-challenges/fibromyalgia/