It can be difficult for patients who suffer from chronic pain to get doctors, relatives and friends to believe in their symptoms when there's no test or exam that proves their aches and pain really exist.

But scientists say overwhelming evidence has emerged in recent years that the condition fibromyalgia is real.

A new study used MRI imaging to show fibromyalgia patients have abnormalities within their brain structure. The fMRI imaging was combined with single photon emission computed tomography.

Fibromyalgia is characterized by a low-threshold for pain and associated with some genetic factors that could make some people more likely to develop the condition.

The study was led by researchers at the University of Michigan Health System and is published in the Dec. 2006 issue of Current Pain and Headache Reports.