Gua Sha is a type of traditional Chinese Medicinal Treatment where your back is scraped with a tool, such as a piece of wood, jade, a spoon, a coin, or a rhino bone (if you're a dick). The way my wife (who's Chinese) explains it, Chinese seem to have a belief that the material type can be significant for the healing process, but I think that is probably a superstition. In any case, the scraping creates small bruising on your skin, which takes ~3 to 4 days to heal. The idea behind it, to which I don't really subscribe, is that the scraping releases toxins that are stored in skin, evidenced by the bruises. The more bruising you show, the more toxins you had in your body (that's why as a first-timer gua-shaer, I had a lot of bruising, see below). Since the scraping releases these toxins, your body is then be able to fight the toxins and remove them from your body. Chinese medicine often deals with the idea of general "toxins," in the body, but there's not much evidence any such thing exists.
Our Gua Sha device, made from Giant Panda Penis, the most magical of all Gua Sha materials
What does have scientific evidence, is that the process does help your body fight aches & pains as well as colds. What western scientists believe, is that the process activates endorphins, your morphine within, to naturally block pain. Also it might help initiate an autoimmune response, similar to X-ray radiation treatment, where X-ray damage actually causes your body to respond with proteins that induce cell death (the X-ray damage does kill cells too, but not enough to kill tumors).
Often the scrapings go along meridian lines used in acupuncture. Since the idea of Qi seems to be more of a religious belief than truth, then probably these meridian lines aren't needed, and you could scrape anywhere for the same effects. Anyways, it's good to have some lines to guide you when you're scraping, right?
Please share any of your experiences with Gua Sha! Did it work for you? Ultimately, I wasn't sick before I tried it, and I wasn't sick afterwards, so at least it didn't hurt... too much!
The not *so* painful markings on my back.