The exact cause of JPFS (or even Fibromyalgia) is unknown.
We do know that often fibromyalgia occurs in families, but so far, a genetic cause has not been found. Abnormalities of neurotransmitters (chemicals that send pain signals to the brain) and some hormones have been found in patients with JPFS, but we do not know if these abnormalities actually cause JPFS.
What we see in JPFS patients is that most are stuck in a ‘vicious cycle’ of pain, fatigue, poor sleep and decreased exercise. Each of these pieces (pain, fatigue, poor sleep, little to no exercise) affects one another. For example, pain causes poor sleep and decreased exercise. In turn, poor sleep increases a patient’s experience of pain. Then, because you have more pain, it becomes harder to sleep. As one continues to have poor sleep, fatigue becomes a major factor. With fatigue, one is even less likely to exercise. Lack of exercise leads to a poor quality of sleep and increased lethargy/fatigue. Lack of exercise also increases the chances that a person will experience pain. One can easily see that this cycle could be very hard to break.
Triggers for JPFS
Often the cycle is triggered by something, like an injury, illness and/or stress. Relationships at home and at school, schoolwork/studies, a death in the family, are just some possible stressful triggers. Also, anything that causes pain or causes someone to stop their normal pattern of exercise can also trigger JPFS.
See also: Causes of Fibromyalgia