This could be a virus, physical or emotional trauma, repetitive stress, sleep deprivation, or some combination of these. Exactly what changes in a fibromyalgia body to cause pain and fatigue is not fully understood. The most recent scientific theories consider the pathology to be located in the central nervous system, where pain signals may be amplified or improperly filtered, causing otherwise innocuous stimuli elicit in severe pain. These all represent important pieces of the puzzle. The good news about fibromyalgia is that there does not seem to be any underlying pathology that worsens.
Treatments therefore focus on alleviating symptoms of pain and sleeplessness.
The difficulties of fibromyalgia tend to cycle. When pain is severe, it interferes with sleep, which worsens pain, mood, cognitive ability, and so on. Treatments aim to break this cycle and reverse its direction. In other words, when reducing pain, allows sleep to become easier, which further reduces pain and fatigue, and so on. The treatments for fibromyalgia sound easy in that they all read like basic practices for good health and well being.