There is mounting evidence that gua sha , an ancient form of Chinese medicine whereby the skin is scraped by a blunt instrument, can indeed be effective for pain relief. The 2,000-year-old treatment, used for generations by Chinese mothers as a home remedy for sick children, has migrated from East to West. Gua sha is now performed throughout Southeast Asia, and in Asian immigrant communities and by traditional Chinese medicine practitioners throughout the world. Since 2005, there have been more than 120 studies on gua sha, mostly investigating its effect on painful, musculoskeletal conditions, such as chronic back pain. In 2009, researchers at Harvard found that gua sha has potential for anti-inflammatory and immunological properties and, in 2011, another Harvard study showed that gua sha reduced liver inflammation in chronic active hepatitis B. Last month, a study investigating the therapeutic benefits of gua sha on 40 patients with chronic neck and lower back pain was published in the American Journal of Chinese Medicine . The participants were randomly assigned to either a treatment group, which received only one gua sha treatment, or a waiting list control group. Seven days after the treatment, both groups were reviewed. Patients in the treatment group reported pain reduction and improved health status as compared to the control group. But, pain sensitivity improved in the chronic neck pain patients in the treatment group but not in those with lower back pain. The researchers suggest this was due to higher pressure sensitivity in the neck area. Romy Lauche, one of the researchers in the University of Duisburg-Essen team, recounted that many patients found sustained relief for more than seven days, and one participant, who had been anxious about the treatment, had unexpected results. "A woman with a back pain rate of seven on a 10-point scale returned for evaluation without any pain. Having examined her before and after, I could see gua sha had eliminated all visible muscle tension. The mountains of tight muscles had disappeared," says Lauche in a phone interview. As with many complementary and alternative therapies, gua sha is not without controversy, mostly due to the distinctive and seemingly severe marks that are a result of the procedure. These marks are not bruises or rashes, but something called petechiae. It looks brutal enough to put off many patients seeking an alternative form of pill-free pain relief. Gua Sha Treatment , a 2001 film, did something to alleviate the misconception. Starring Hong Kong film star Tony Leung Ka-fai, it is a story about Chinese-American immigrants who come face to face with cultural misunderstanding when a doctor discovers the shocking gua sha marks on the school-aged son and calls the authorities. It's a tale with a happy ending. But not all gua sha treatments are equal. Annie Tong, a Hong Kong resident, had the treatment a decade ago in a Kowloon clinic, and still remembers the pain. "It was uncomfortable, and my back was as red as a radish. It hurt for days, and there was little relief. I wouldn't try it again," she says. Dr Gladys Leung, a TCM practitioner and adviser to the Langham Place Hotel's TCM-based Chuan Spa, believes gua sha needn't be painful. It depends on the communication between patient and practitioner, and the skin sensitivity of the patient. "A practitioner may be doing it too strongly without asking for the patient's feedback," she says. Dr Wu Yue, a TCM practitioner in Singapore who specialises in acupuncture, says there are different degrees of firmness for different degrees of patient pain. "It depends on the qi and the state of congestion in blood flow. A firm stroke would be used for very blocked qi indicated by severely tight muscles." Dr Arya Nielsen, director of acupuncture at Beth Israel Medical Centre's Department of Integrative Medicine in New York, has spent a great deal of her career teaching gua sha to doctors throughout Europe and North America. She has written a textbook on fundamental gua sha, led research to prove evidence of gua sha efficacy for pain and considers the treatment "a simple medical miracle". Nielsen has submitted safety protocols for gua sha and cupping therapies to eliminate risks and raise the calibre of practice standards. Pain should not be part of a patient's experience during the procedure, she says. The greatest misconception about gua sha is that the treatment causes bruises. "Gua sha does not cause bruising. Bruising represents traumatic bleeding and injury to the tissue," says Nielsen. The red marks seen after a gua sha treatment represent the flight of red blood cells in the surface tissue. "When there is blood stasis [characterised as fixed, persistent or recurring pain], gua sha will cause the cells to go 'outside' the vessels, but they will immediately begin to be reabsorbed." This process releases pain, enhances blood flow and improves function of the nervous system. During the treatment, special oil is applied for its protective, detoxifying or relaxing purposes depending on the requirements of the patient. The practitioner begins the procedure by scraping or press-stroking with a smooth-edged instrument traditionally made from jade, horn or metal. Practice guidelines today require that the tools be sterilised or disposable to eliminate infection. Press-stroking is unidirectional and repeated until the petechiae or red dots appear. From the colour of the petechiae, it is possible to see if the blood stasis is a recent (lighter red) or chronic (dark red or purple to black) stagnation. Normally, the red marks disappear completely within three to seven days. After the treatment, patients can feel a variety of symptoms. They notice, says Nielsen, "an immediate shift in pain, range of motion, fever, cough, nausea, vomiting, wheeze and so on". Nielsen says the treatment is not advised for those with sunburn, rash, wounds, or over moles or pimples. Many doctors believe that pregnant women or those with diabetes and some cancers are also not suitable for gua sha. But Nielsen disagrees with this, saying that "it produces a protective immune response at the internal organs". Researchers from the Korea Institute of Oriental Medicine did a systematic review of controlled clinical trials of gua sha and published their findings in 2010 in the journal BioMed Central . They searched 11 databases and found seven trials, three of which the researchers say showed favourable effects on pain reduction but were of poor study quality. "Current evidence is insufficient to show that gua sha is effective in pain management," they conclude. Another study published last year in the journal Pain Medicine by German researchers randomly assigned 48 patients with chronic neck pain to either one gua sha treatment or local thermal heat pad treatment and followed up seven days later. The researchers concluded that gua sha has beneficial short-term effects on pain and functional status in chronic neck pain patients, but its value in the long-term remains to be seen.