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Gua Sha: An Essential Diagnostic Tool for Acupuncturists

Updated: Nov 13, 2023

Gua sha is an East Asian medicine technique that involves scraping the skin with a smooth-edged tool to improve circulation, relieve muscle tension, and treat internal diseases. In addition to its therapeutic benefits, gua sha can also be used as a diagnostic tool to identify the underlying cause of a patient's symptoms. By observing the color and appearance of the sha, as well as the time it takes for the sha to appear and fade, practitioners can gain valuable insights into a patient's condition and the effectiveness of treatment.

Woman receiving a gua sha treatment

In this article, we will explore the use of gua sha as a diagnostic tool, including the importance of consistent technique and the selection of an appropriate gua sha tool. We will also discuss the different color patterns of sha and how they can be used to diagnose various conditions. Finally, we will explore time-based diagnosis in gua sha and how the time it takes for sha to arrive and fade can provide additional insight into a patient's condition. If you are interested in the history of gua sha check out this article. Overall, gua sha is a valuable tool for traditional Chinese medicine practitioners and can provide significant benefits for patients.

What is Sha?

Sha is a term used in traditional Chinese medicine (TCM) to describe the visible rash-like mark that appears after using the gua sha technique. In scientific terms, sha results from the extravasation of cellular material with a localized inflammatory response that begins a targeted healing cascade. As the metabolic waste from the procedure is reabsorbed into the body, circulation increases, and the body's anti-inflammatory chemicals are upregulated, systematically reducing inflammation.

In TCM, illness can arise from xie qi (evil qi) or pathogenic influences lodged in the channel systems of the body. Gua sha is a technique used to open the pores and release the exterior while moving qi and blood internally. These actions remove the latent pathogenic influences and leave behind visual markers called sha. These pathogenic influences are classified as one or more of the six pathogenic influences: wind, cold, heat, dampness, dryness, and summer heat. As these pathogens are dislodged, the law of signatures takes effect, leaving behind visual clues. An astute clinician can determine the pathogenic influence's type, strength, and channel location by observing and understanding these clues.

In this context, channel location refers to the channel system in which the xie qi is lodged and not a physical location on a primary meridian pathway. From the most superficial to the deepest, the five-channel systems are the sinew channels, luo channels, primary meridians, divergent channels, and eight extraordinary vessels. Understanding which channel system is involved will determine the best course of treatment. For example, a stiff neck caused by acute wind cold invasion differs significantly from a stiff neck caused by a lingering divergent channel pathogen. Wind cold evasion should be a straightforward course of treatment, whereas a divergent pathogen can be challenging to treat effectively.

Consistent Technique

Having a consistent technique is essential when using gua sha for diagnosis. If the clinician's technique varies greatly in terms of pressure or speed from one treatment to the next, it will be difficult to establish a baseline for comparisons. The key is to use consistent, even strokes to understand how different patients will react and how individual patients change from treatment to treatment. As clinicians, our patients can be our best teachers if we take the time to observe, listen, and understand how they respond to our treatments. A consistent, systematic approach is best, and clear; honest self-assessment is crucial for learning from our patients.

Selecting the Proper Tool

The type and quality of the gua sha tool used for treatment are important factors to consider. Implements with rough edges can cause abrasion to the skin, which is commonly seen with some stone, porcelain, and horn tools. Using a magnifying glass to closely examine the surface of a poorly made gua sha tool or one made with the wrong materials, you will see a rough, sandpaper-like surface that is often not visible to the naked eye. These tools will bring up redness and petechiae with only a few passes, but this is not sha. This is skin damage, and the clinician must stop treatment before true sha is present. To achieve accurate diagnostic results, it is essential to use a high-quality gua sha tool. A metal tool with a polished edge that is not sharp or too thick is ideal. A tool with a wide edge may be useful for treating muscle-skeletal conditions, but it will not be easy to bring up sha. These wider-edged tools are commonly sold as IASTM (Instrument Assisted Soft Tissue Mobilization) tools, but they are unsuitable for diagnostic purposes or treating internal diseases.

Diagnosis by Color

Gua sha as diagnosis purple sha with yellow ghosting..
Fading sha revealing a yellow ghosting color.

Sha is a term that often refers to two distinct color patterns that can occur during or after gua sha therapy. The primary color pattern forms during the therapy and can continue to develop for up to an hour after the procedure ends. This color is related to blood levels, cou li (a term referring to where the xie qi may be lodged in the body), or problems with the sinew channel. The second color pattern, known as "ghosting," appears as the primary color fades and may indicate an underlying condition. For example, a primary color pattern of deep purple likely indicates blood stagnation and a yellow ghosting color points to a warm phlegm condition. The ghosting pattern is often related to the overall constitution of the individual, but it can also reveal lingering pathogenic influences in deeper channel systems within the body.

Diagnosis by Time

The amount of time it takes for sha to arrive or fade is an important diagnostic marker. The arrival time of sha is related to the depth of the pathogenic influence. Sha that appears quickly is more superficial than sha that takes longer to form. For example, if a patient has an acute wind invasion, sha is likely to appear quickly because the pathogenic influence is near the surface. However, since the divergent channels are one of the deepest channel systems in the body, xie qi located there may take several minutes or even multiple treatments before sha appears.

The fading time of sha is related to the strength or amount of pathogenic influence. If sha fades quickly, a shorter course of treatment may be necessary, but if sha lingers for several days or more, the pathogenic influence is strong, and a longer course of treatment will likely be needed. The patient's constitution can also affect fading time. A more vibrant and active individual may be able to clear sha faster than a sedentary patient with weak wei qi.


Gua sha is an effective treatment option and a valuable diagnostic tool when used systematically. Proper technique and a high-quality gua sha tool are essential for achieving consistent results. By analyzing the color and appearance of sha, as well as the time it takes for sha to arrive and fade, practitioners can gain valuable insights into a patient's condition and the effectiveness of treatment. Overall, gua sha is a valuable tool for traditional Chinese medicine practitioners and can provide significant benefits for patients.

Chart of diagnosis by color of sha for acupuncturists using gua sha treatments.

Chart of diagnosis by fade and arrival time of sha for acupuncturists using gua sha treatments.


Xiuqin Z, Wanshan, Hao. Holographic Meridian Scraping Therapy. Beijing: Foreign Languages Press; 2000.

Cecil-Sterman A. Advanced Acupuncture: A Clinical Manual. Ann Cecil-Sterman, PLLC; 2013.

Nielsen A. Gua sha Traditional medicine for pain, inflammation and immune support. 2012;412(August 28):1.

Unschuld PU, Tessenow H, Jinsheng Z. Huang Di Nei Jing Su Wen, An Annotated Translation of Huang Di’s Inner Classic - Basic Questions. Berkely: University of California Press; 2011.

About the Author

Mark Parzynski. DAOM, L.Ac., is a licensed acupuncturist and educator with a diverse background in the field. He has studied in the United States, Japan, and China and uses a range of unique therapeutic approaches to create personalized treatment plans for his patients. Dr. Parzynski has over a decade of experience as a clinical supervisor and has taught graduate students and clinicians.

In addition to his work in acupuncture, Dr. Parzynski is also a skilled craftsman and silversmith. He began making teishin and gua sha tools as an acupuncture student. His passion as an artisan has continued, and for over a decade, he has been making tools for practitioners worldwide, including some of Japan's most renowned masters.

Dr. Parzynski is also a Chinese internal martial arts practitioner, which he incorporates into his acupuncture practice and daily life. He was a senior student of the late Sifu Gregory Fong and has taught Taiji Quan, Yi Quan, and Qi Gong since 2006.

For acupuncture tools and classes provided by Dr. Parzynski, visit

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