Gua Sha is a technique used to open the pores to release the exterior - mimicking the effect of sweating - to expel an acute cold/flu, improve circulation, and move congested fluids out of the tissues and muscles to be expelled by the body. This is accomplished using a smooth-edged instrument being scraped across the skin to elicit raised, red marks (sha).
This practice is often used for pain, tenderness and muscle tension associated with acute or chronic disorders, and also to treat and prevent the common cold, flu, bronchitis, and asthma, as suggested above.
Like cupping, gua sha can often leave red or bruise-like marks that may last for several days after treatment.