Cao Gio in Vietnam: What the Red Marks Mean, and When to Skip It

Cao gio is Vietnamese coin scraping, and the striped red marks you see on necks and backs around Saigon are its result, not an injury. Written cạo gió in Vietnamese, it means scraping (cạo) the wind (gió): a coin or another smooth edge is drawn over skin slicked with balm or oil until red lines come up. Families reach for it when someone feels a chill coming on. The marks fade over a few days to two weeks. The evidence for any health effect is thin, so the useful questions are who should skip it and what to expect if you try it.

What Cao Gio Is, and How It Is Done

The usual trigger is trúng gió, literally “hit by wind.” Our guide to Vietnamese wellness culture and spa etiquette describes it as the everyday explanation for sudden illness: a headache out of nowhere, nausea, dizziness, aching after sitting in a draft or getting caught in the rain. The household answer is to scrape.

A dermatology case report on coining, published on PubMed Central, translates the name as “scratch out the wind” and describes the method: lubricant first, then a coin or spoon stroked firmly in one direction, line beside line, until petechiae appear. Wikipedia’s article on gua sha, the Chinese name for the same family of techniques, lists ceramic spoons, coins, jade stones and water buffalo horn among the tools, and gives “coining” and “spooning” as English names.

At Chạm Spa the coin is replaced by a smooth-edged scraping tool and warming ginger, and the work usually covers the back and shoulders.

Why the Red Marks Appear, and How Long They Last

The stripes are not a burn and not a rash. They are petechiae, which Cleveland Clinic’s overview of gua sha defines as “tiny spots of bleeding under the skin caused by broken capillaries.” Firm, repeated strokes break the smallest vessels just below the surface, and the escaped blood shows through as dots that merge into lines. Chạm Spa’s page on its ginger scraping add-on describes them as red or purplish, painless to the touch and visible within minutes, and calls them “the intended result rather than a side effect.”

How long they last depends on how heavy they are. Chạm’s page says roughly three to seven days. The case report says the heavier, bruise-like marks of vigorous coining, which it calls ecchymoses, “usually resolve spontaneously within one to two weeks.”

Within Đông y, the traditional medicine framework, the depth of color is read as a sign of how much stagnation was released. That is a traditional reading, not a measurement.

The Folk Belief and What Is Actually Known

The belief runs like this: wind gets into the body and becomes trapped, scraping lets it out, and the marks show it leaving. Chạm’s own page frames it as a belief: “in traditional understanding the technique releases trapped ‘wind’,” the word for that heavy, achy, coming-down-with-something feeling.

What is known is narrower. Cleveland Clinic notes that gua sha “has been shown to increase microcirculation in the areas where it’s performed,” and the case report cites a pilot study in healthy volunteers in which local microcirculation rose fourfold for the first seven and a half minutes. Beyond that, the same Cleveland Clinic article says there is “not enough high-quality research to definitively declare the benefits of this technique.” It adds that a 2010 review “didn’t find enough evidence to prove pain relief benefits,” while one small later study suggested longer-lasting relief from chronic lower back pain than heat therapy. Wikipedia is blunter: gua sha “lacks high-quality evidence of clinical benefit.” The authors of a 2010 systematic review of gua sha for musculoskeletal pain, published in the journal Chinese Medicine, rated the trials that reported benefits as poor or low quality and concluded that “current evidence is insufficient to show that Guasha is effective in pain management.”

Chạm’s page notes that many guests find the scraping relieving while it happens. But no good evidence shows that it shortens a cold or flu, and a fever is a reason to see a doctor, not to scrape.

Coin Scraping, Facial Gua Sha and Cupping Compared

Visitors often confuse three techniques that work on the skin.

The difference that matters most is pressure. Chạm’s facial gua sha treatment page puts it plainly: “Where body gua sha uses firm scraping strokes, the facial version is deliberately light — the aim is to move fluid, not to redden the skin.” The same page lists the facial as suitable in pregnancy, which body scraping is not. Our guide to traditional Vietnamese massage covers cupping as part of that tradition, and Cleveland Clinic’s page on cupping therapy covers its marks and risks.

Who Should Skip It

• Blood thinners or a bleeding disorder. The technique works by breaking capillaries. Cleveland Clinic names aspirin, Coumadin and apixaban, and the case report says coining is contraindicated with bleeding disorders, von Willebrand disease, and antiplatelet or anticoagulant medicines.
• Broken, irritated or sunburned skin. Cleveland Clinic says it “should never be performed over irritated or inflamed skin, like rashes, wounds or sunburns.” Chạm adds moles across the area. If you have arrived from the beach burned, read what you can book with a sunburn first.
• Skin conditions, or skin that bruises easily. Cleveland Clinic lists eczema and psoriasis, and the traditional massage guide suggests something gentler if you bruise easily.
• Pregnancy. Chạm does not perform scraping at any stage of pregnancy; a pregnancy massage with side-lying support is the alternative.
• A fever or feeling acutely unwell. Chạm’s page puts it in one line: “Fever or acute illness where you should be seeing a doctor rather than a spa.”
• Diabetes, circulation problems or chemotherapy. Cleveland Clinic lists all three as reasons gua sha may not be a fit. Ask your doctor first.

Cleveland Clinic calls gua sha generally safe. The case report also lists rare complications, from contact dermatitis to minor burns, which is why the list above matters.

The Marks at the Beach, in Photos and at the Doctor

The marks stay visible for days. Chạm’s page is direct about timing: if you have anything coming up where visible marks would be unwelcome, “a beach holiday, a wedding, anything sleeveless,” choose infrared light therapy for warmth without marks or a warm herbal patch instead. Its aftercare is to keep the area warm and avoid a cold shower for a few hours, so plan a swim for later rather than straight after.

In photos, the stripes can read as an injury to anyone who has not seen them before. Wikipedia notes that among Vietnamese and other Southeast Asian communities in the United States, the marks “have been mistaken for signs of physical abuse,” and the case report says they can mimic child or elder abuse. If you see a doctor for anything while the marks are visible, mention cao gio so they are read correctly.

Stripes on a stranger’s neck in a Saigon café are a household remedy, not a warning sign, as our guide to what is and is not a risk at a massage in Vietnam explains.

Adding Ginger Scraping to a Treatment at Chạm Spa

Chạm’s version is Traditional Ginger Scraping, a 50,000 ₫ add-on that uses warming ginger and a gua sha scraping technique. It is added to a massage or body treatment rather than booked alone.

1. Check the list above. When you book, mention blood-thinning medication, pregnancy, sunburn or a skin condition.
2. Check the next two weeks. A beach trip, a wedding or a sleeveless outfit means choosing infrared light therapy or a herbal patch, both also 50,000 ₫.
3. Ask for it. Mention it when booking on Zalo or WhatsApp, or ask your therapist during the session. A therapist may suggest an add-on; you are never obliged to take it.
4. Expect a strong scraping sensation rather than pain. Pressure is adjusted on request, and the add-on page says “the technique works perfectly well at moderate pressure.” Speak up if it becomes uncomfortable.
5. Let the marks fade on their own. Keep the area warm, skip a cold shower for a few hours, and use no cream; none is needed.

For the other two warming options, see all three traditional add-ons side by side. If you are still choosing the main treatment, which type of massage suits what you want sorts the menu by goal.

If You See the Stripes, or the Word on a Menu

Striped red marks on a back in Saigon usually mean cao gio, a household remedy. The marks are bleeding under the skin, not a burn, and they fade within a few days to two weeks. Try it as a local tradition with your eyes open rather than as treatment, and skip it if anything on the list above applies to you. For warmth without marks, choose infrared or a herbal patch.

Frequently Asked Questions About Cao Gio

If Chạm Spa has looked after you, it helps other guests to hear about it. Leave a review