In a Rheumatology Journalarticle researchers report on how they measured the blood flow and skin temperature in the area of 5 known tender points of both Fibromyalgia syndrome (FMS) patients and a control group without the syndrome. Blood flow was measured using a laser Doppler flowmetry and skin temperature was measured with an infrared thermometer.

They found that the blood flow was reduced in FMS patients as was the skin temperature. Their hypothesis is that FMS originates in the muscle and disturbances in micro-circulation in the affected areas. The pain at the tender, frequently experienced by FMS patients, correlates with the reduction of blood flow in the area. Because of the poor blood flow the researchers concluded that there was probably a lack of oxygen reaching the muscles in the tender points.

The researchers felt that the reduced blood flow in the tender point areas may be due to the regulation of blood flow rather than in any changes in the structure of the micro-circulation.

The local pain experienced by FMS patients, the researchers believe, is most likely related to temporary oxygen depletion at the trigger points.