The single most obvious sign of fibromyalgia is pain.
It can happen all over the body and will come and go randomly. Many experience pain that is related to weather changes. Some report they experience pain for months at a time. As you can imagine, this can be a debilitating ailment if you have to somehow manage your pain for weeks at a time through going to work and outside engagements.
Pain may be decreased by using over the counter medications, or by using heated patches that often have menthol in them that attach right to the skin on the affected area. They are a relatively cheap price to pay for a few hours of pain relief.