Many scientific studies have attempted to quantify this effect. Does it have measurable biochemical effects? Does everyone experience it? If a person has tension headaches, for instance, does this relaxation effect actually help them? And if so, how long does the effect last?
One study done recently in Sweden says the answer is yes, and the effects seem to last for months.
Fibromyalgia is a disorder characterized by widespread musculoskeletal pain, described as a constant dull ache, typically arising from muscles. It effects 2% of general population and women are much more likely to develop it than are men by a ratio of 9:1.
Sufferers can be chronically tired, bedridden much of the time and suffer pain that feels like body-wide bruising. It can hurt even to be touched by another person. Restful sleep is difficult. Many people who have fibromyalgia also have tension headaches, temporomandibular joint (TMJ) disorders, irritable bowel syndrome, anxiety and depression.
Fibromyalgia is not well understood at all. It can develop gradually, or have a sudden onset triggered by a traumatic event like a car accident. Its cause is not known. The best current explanation of what happens is that somehow the sufferer’s brain simply becomes more sensitive to pain (“central augmentation of pain sensitivity”), but how or why that happens is more or less anyone’s guess.