Doctors do not use lab tests to diagnose
fibromyalgia. The results of lab tests done on people
with fibromyalgia should be normal unless another condition is present.
You may have lab tests to rule out other diseases or to find out
whether you have another disease in addition to fibromyalgia. Fibromyalgia may
occur along with other joint and muscle (rheumatic) diseases, such as
rheumatoid arthritis. Finding these other conditions is important, because
they may need different treatment.
Many studies link fibromyalgia and depression. In fact, about three out of every 10 people with fibromyalgia also have major depression at the time of their diagnosis.
Some researchers feel that depression leads to changes in brain chemistry. Others look at abnormalities of the sympathetic nervous system -- the part of the nervous system that determines how you handle stress and emergencies. These abnormalities, they contend, may lead to the release of substances that cause more sensitivity to pain...