The common causes of Gua Sha include wind and cold attacking the surface, blood stasis and obstruction or cold and wet immersion. 1. wind and cold attack surface: wind and cold invade the body surface, the guard outside not solid triggered by cold, scraping gua sha will appear small dots of black gua sha, suggesting that the evil in the surface. 2. blood stasis blockage: due to the back of the meridian, qi and blood running poorly, blood stasis blockage, caused by muscle stiffness and pain, can see purple-black gua sha points. 3. Cold and damp immersion: living in a cold and damp environment or like to eat fat, sweet, thick and greasy greed cold patients Gua Sha is mostly greenish purple, suggesting that the body of cold and dampness is heavy. Push back can activate blood circulation, the body of the wind, cold and dampness in the form of gua sha discharged from the body, for health care, sub-health state, cold and fever and painful diseases have more obvious effect. But it is worth noting that: body surface sores ulcerated, there is an unknown reason mass or acute injury fracture people avoid; have serious circulatory disorders such as cardiovascular and cerebrovascular disease, liver and kidney insufficiency, generalized edema people avoid using.