Context: Gua Sha, therapeutic surface frictioning that intentionally raises transitory petechiae and ecchymosis, is a traditional East Asian healing technique also known as cao gio, coining, scraping, and spooning. There are case reports in Western literature but no studies on the physiological effects of Gua Sha.

Objective: To study the microcirculatory effects of Gua Sha on the skin and subcutis in humans to elucidate physiological mechanisms responsible for the clinically observed pain-relieving effect of this treatment

Design: Laser Doppler imaging (LDI) was used to make sequential measurements of the microcirculation of surface tissue before and after Gua Sha treatment in 11 healthy subjects. The effect of Gua Sha treatment on the microcirculation of surface tissue was expressed as changes from baseline in arbitrary perfusion units (PU).

Setting: The study was conducted at the Department of Nephrology, Unit of Circulation Research, University Hospital of Essen, Germany.

Subjects: Subjects were volunteers from the nursing and physician staff of the Kliniken Essen.

Intervention: A single Gua Sha treatment was applied to an area of each subject's back.

Outcome measures: Change in microcirculation was measured in PUs. Change in myalgia was subjectively reported and confirmed by manual palpation.

Results: Gua Sha caused a fourfold increase in microcirculation PUs at the treated area for the first 7.5 minutes following treatment and a significant increase in surface microcirculation during the entire 25 minutes of the study period following treatment (P < .001). Females showed significantly higher rates of response than males (P = .003). Each subject experienced immediate decrease in myalgia in both the site treated, in the related distal control site, and in some cases, other distal sites. Pain relief persisted to some extent up to the follow-up visit. There were no adverse reactions.

Conclusion: Gua Sha increases microcirculation local to a treated area, and that increase in circulation may play a role in local and distal decrease in myalgia. Decrease in myalgia at sites distal to a treated area is not due to distal increase in microcirculation. There is an unidentified pain-relieving biomechanism associated with Gua Sha.