The actual purple bumps that appear when you scrape is due to the excess of cold and dampness in your body, and after scraping causes the subcutaneous capillaries to rupture, the blood seeps out, the skin pores open, and the damp and cold gas in the blood leaks out through the pores. The heavier the color of the purple bumps that appear, the larger the area, the more dampness and coldness in your body, and the more you need to scrape for treatment. The actual fact is that you can find a lot of people who are not able to get a good deal on a lot of things. The next scrap of gua sha can be done when the color of the gua sha is not too obvious, usually in about 3-5 days.