REN-17 (Shan Zhong) Chest Center

What does REN-17 Shan Zhong do?

Shan Zhong REN-17 is the great point of the chest and of qi. It carries three classifications at once — Front-Mu point of the Pericardium, Hui-Meeting (influential) point of Qi, and a Point of the Sea of Qi — and it is the convergence of the Conception Vessel with four channels. No other point on the front of the body holds that combination, and it is the reason a single point between the breasts is reached for whenever qi is stuck, rebelling upward, or too weak to gather in the chest.

• Regulates qi and unbinds the chest — the defining action. Chinese medicine treats the tight, oppressed, band-around-the-chest sensation as a disorder of qi in its own right, and REN-17 is its first-line point. Sacred Lotus sources & references record the action in exactly these terms.
• Benefits and regulates gathering qi (zong qi) — the qi formed in the chest from the air taken in by the Lungs and the essence extracted by the Spleen, which drives respiration and the movement of blood through the vessels. REN-17 is the point where that qi is said to gather, and this is the substance behind its Hui-Meeting of Qi classification.
• Descends rebellious Lung and Stomach qi — for qi travelling the wrong way: cough, wheezing, shortness of breath, hiccup, belching, nausea and difficulty swallowing. The Conception Vessel runs the length of the front midline, and REN-17 sits where the airway and the gullet both pass behind it.
• Benefits the breasts and promotes lactation — REN-17 lies midway between the nipples, and it is the single most consistently recorded point of the classical corpus for insufficient lactation, blocked milk flow, breast distension and mastitis.
• Calms the spirit through the Pericardium — as Front-Mu of the Pericardium, the organ classical theory places around the heart as its protective wrapping, REN-17 is used for palpitations, anxiety and the emotional constraint that presents as a tight chest and sighing.

Source: Sacred Lotus sources & references (existing action record; Front-Mu, Hui-Meeting of Qi, Sea of Qi and Meeting Point classifications); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 517); Chinese Acupuncture & Moxibustion (p. 239); Hui-Meeting point scheme per the Nan Jing (Classic of Difficulties), Difficulty 45; cross-referenced against multiple online sources.

What is REN-17 Shan Zhong used for?

Shan Zhong REN-17 is used above all for the chest — tightness, pain, cough and wheezing — and for the breasts, especially insufficient lactation. The indications below are those carried in Sacred Lotus sources & references together with those set out in the standard reference literature. They describe traditional use, not proven treatment, and this point carries the sternal cautions set out under needling.

• Fullness, tightness and oppression of the chest
• Pain in the chest
• Asthma and wheezing
• Cough and shortness of breath
• Palpitations
• Insufficient lactation; milk that will not flow
• Breast distension, breast pain and mastitis
• Hiccup and belching
• Difficulty swallowing; a sense of obstruction in the gullet
• Nausea and vomiting
• Sighing, anxiety and emotional constraint felt in the chest
• Distension and pain of the flanks and ribs

Source: Sacred Lotus sources & references (existing indication record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 517); Chinese Acupuncture & Moxibustion (p. 239).

Where is REN-17 Shan Zhong, and how is it used in practice?

Shan Zhong sits on the front midline, on the body of the breastbone, level with the fourth intercostal space — in most adults that is level with the nipples, midway between them. Sacred Lotus sources & references give it in both of these terms: level with the fourth rib space where it joins the sternum, and midway between the nipples. It is one of the easiest points on the body to find and one of the most used, because it is the point a practitioner reaches for whenever the presenting complaint is felt in the chest — whether as breathlessness, as constriction, or as an emotional weight.

Which points is REN-17 combined with?

• For insufficient lactation — the classical core combination is REN-17 with Ru Gen ST-18 directly beneath the breast, Shao Ze SI-01 at the corner of the little fingernail, Zu San Li ST-36 to build qi and blood, and Tai Chong LIV-03 where the milk is blocked by constrained qi. A published analysis of 120 clinical studies of acupuncture for postpartum insufficient lactation found exactly this five-point group — Danzhong CV-17, Rugen ST-18, Zusanli ST-36, Shaoze SI-01 and Taichong LR-03 — to be the highest-frequency combination in the literature (Zhongguo Zhen Jiu 2020;40(10):1138–42, PMID 33068361). That is an unusually clean confirmation that a classical combination is still the one in actual use.
• For chest oppression and wheezing — with Nei Guan P-06 at the wrist, the confluent point of the Yin Linking vessel and the standard distal point for the chest, and with Fei Shu BL-13, the Lung Back-Shu point behind. Feng Long ST-40 is added where phlegm dominates.
• For hiccup and rebellious qi — with Tian Tu REN-22 in the suprasternal notch and Zhong Wan REN-12, the Front-Mu of the Stomach and Hui-Meeting point of the Fu organs, on the upper abdomen.
• For palpitations and anxiety — with Nei Guan P-06 and Shen Men HT-07, the Yuan-Source point of the Heart channel, in the standard spirit-calming trio.
• For qi deficiency of the chest — with Qi Hai REN-06 on the lower abdomen and Zu San Li ST-36; the pairing of the chest's qi point with the abdomen's is a long-standing structure in tonifying prescriptions.

Where does REN-17 sit among its category peers?

REN-17 is unusual in belonging to three separate classification systems at once, all of them held in Sacred Lotus sources & references.

• As one of the eight Hui-Meeting points, it governs qi across the whole body, as Ge Shu BL-17 governs blood, Zhang Men LIV-13 the zang organs, Zhong Wan REN-12 the fu organs, Yang Ling Quan GB-34 the sinews, Xuan Zhong GB-39 the marrow, Da Zhu BL-11 the bones and Tai Yuan LU-09 the vessels. All eight are held here. The practical consequence is that REN-17 can be selected for a qi disorder anywhere, not only in the chest.
• As Front-Mu point of the Pericardium, it is one of the twelve Front-Mu points, the places on the front of the trunk where each organ's qi gathers and where its disorders show as tenderness. Sacred Lotus sources & references hold the full set of twelve. REN-17 is the natural partner of Jue Yin Shu BL-14, the Pericardium's Back-Shu point behind it — front and back of the same organ.
• As a Point of the Sea of Qi, it belongs with Da Zhui DU-14 and Ya Men DU-15 behind and Ren Ying ST-09 above, the group named in the classical Four Seas scheme for the sea of qi that gathers in the chest.

Source: Sacred Lotus sources & references (REN-17 record; Hui-Meeting, Front-Mu and Sea of Qi point sets queried in full); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 517); Chinese Acupuncture & Moxibustion (p. 239); PMID 33068361; cross-referenced against multiple online sources.

Where is REN-17 located?

• A Manual of Acupuncture (p. 517): On the midline of the sternum, in a depression level with the junction of the fourth intercostal space and the sternum.
• Chinese Acupuncture and Moxibustion (p. 239): On the anterior midline, at the level with the fourth intercostal space, midway between the nipples.

How is REN-17 Shan Zhong needled, and why is perpendicular insertion ruled out?

Stated plainly: REN-17 lies on the body of the breastbone, and the reference literature records insertion at the sternal points as transverse or oblique only — never perpendicular. The reason is anatomical. A minority of people are born with a sternal foramen, a small congenital hole through the breastbone, and the imaging studies place that foramen most often in the lower sternal body, at the level of the fourth to sixth costochondral junctions — which is REN-17's own level. A fatal case following acupuncture through such a foramen is on record. Everything below is recorded as neutral reference data describing what the textbooks and the anatomical literature state. It is not instruction, and this page does not teach technique. Needling is carried out only by a qualified, licensed practitioner.

The angle and depth the texts record

• Sacred Lotus sources & references record subcutaneous (transverse) insertion of 0.3 to 0.5 inch, with moxibustion applicable. "Subcutaneously" is the operative word: the needle is recorded as running just under the skin along the surface of the bone, not into or toward it.
• Chinese Acupuncture & Moxibustion (p. 239) and Deadman & Al-Khafaji (p. 517) both record transverse or oblique insertion at REN-17 in a comparable shallow range, commonly directed downward, upward or laterally toward the breast depending on the intended effect.
• All three records converge on the same restriction. That is worth noting in itself: for most points the sources differ on depth, but for the sternum they agree.
• Moxibustion is recorded as applicable, and REN-17 is frequently treated with moxa or with acupressure rather than needled at all.

The sternal foramen — and why it matters more at REN-17 than higher up the sternum

A sternal foramen is a congenital opening left where the two halves of the sternum fail to fuse completely during development. It is harmless in itself, causes no symptoms, and most people who have one never know. It matters here for one reason: it is a hole straight through the front wall of the chest.

• How common is it? A meta-analysis pooling 35 studies and 16,666 subjects found an overall prevalence of a foramen in the sternal body and/or xiphoid process of 8.9 per cent (95% CI 6.5–11.7), and 6.5 per cent for the sternal body alone. It was roughly twice as common in men as in women (12.2 versus 6.8 per cent), and varied by population — around 13.9 per cent in South American and 13.6 per cent in African series against 6.2 per cent in North American ones. Mean diameters were about 4.7 mm across and 5.6 mm vertically (Pasieka P et al., Surg Radiol Anat 2023;45(5):623–635, PMID 36918418, PMC10129975, DOI 10.1007/s00276-023-03116-9). This sits squarely inside the roughly 5 to 13 per cent range reported by the individual imaging series.
• Where in the sternum — the measured answer. A CT study of 1,180 patients found sternal foramina in 11.6 per cent and reported that 78.8 per cent of them lay in a typical position in the lower sternal body at the level of the fifth costochondral junction. The structure lying directly behind the foramen was mediastinal fat in 53.3 per cent of cases, the anterior pericardium in 32.1 per cent and lung tissue in 14.6 per cent. The authors named the fourth to sixth costochondral junctions as the danger zone for blind sternal procedures (Boruah DK et al., Skeletal Radiol 2016;45(12):1619–1628, PMID 27629288, DOI 10.1007/s00256-016-2473-9). REN-17 is at the fourth intercostal level, at the upper edge of that zone. This is the honest position: the foramen is not at REN-17 by definition, it is usually a little lower, but REN-17 is inside the band the anatomical literature identifies rather than safely above it.
• What lies behind it. A CT study examining the relationship of sternal foramina to the chest organs found the directly adjacent structure to be lung in 53.3 per cent and mediastinal fat in 33.3 per cent, with the heart directly adjacent in 20 per cent; the author noted that a needle inserted deeply enough would eventually perforate the pericardium in every case examined, and that in that sample pericardial puncture would not have occurred at depths under 2.5 cm — while cautioning against reading a general safe threshold from preliminary data (Gossner J, Anat Res Int 2013;2013:780193, PMID 24224092, DOI 10.1155/2013/780193).
• The documented fatal case. A case report in The Lancet records fatal cardiac tamponade — bleeding into the sac around the heart — after acupuncture passed through a congenital sternal foramen (Lancet 1995;345(8958):1175, PMID 7723561, DOI 10.1016/s0140-6736(95)91004-2). This is the case the anatomical literature returns to whenever sternal foramina are discussed, and it is why radiology papers on the variant name acupuncture alongside bone-marrow aspiration as a procedure for which it matters.

The proportion of the risk

This is a rare event, and it should be described as one. A meta-analysis of prospective clinical studies estimated serious adverse events in acupuncture at approximately 1 per 10,000 patients and around 8 per million treatments, concluding that acupuncture is among the safer treatments in medicine (Bäumler P et al., BMJ Open 2021;11:e045961, PMID 34489268, DOI 10.1136/bmjopen-2020-045961). A systematic review of vascular injuries from acupuncture identified 31 published cases in total across the world literature, of which pericardial tamponade was the commonest serious event (Bergqvist D, Int Angiol 2013;32(1):1–8, PMID 23435388). The sternal foramen is best understood not as a common danger but as the precise reason a long-standing technical convention exists: the texts have always recorded the sternal points as transverse-only, and modern imaging has since supplied the mechanism and located it.

Source: Sacred Lotus sources & references (existing needling record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 517); Chinese Acupuncture & Moxibustion (p. 239); PMID 36918418 (PMC10129975); PMID 27629288; PMID 24224092; PMID 7723561; PMID 34489268; PMID 23435388 — each record verified resolvable and checked for retraction status before citation.

What does the name Shan Zhong mean?

Shan Zhong means "Chest Centre" — and it is the centre in more than one sense. The characters are commonly romanised as Shan Zhong, Dan Zhong or Tan Zhong; all three spellings refer to this same point, and the research literature indexes it most often as Danzhong. The first character names the space within the chest where the classics say the qi of the whole body gathers and where the Pericardium sits; the second is simply "centre". Sacred Lotus sources & references translate the name as Chest Center. The point lies at the geometric middle of the front of the chest, and the classical texts also call this region the "sea of qi" of the upper body — a name that describes what the point is for.

Why does REN-17 carry three classifications, and what does each one add?

Most points carry one classification or none. REN-17 carries three, and each explains a different part of its clinical range.

• Front-Mu point of the Pericardium. The Front-Mu points are the twelve places on the front of the trunk where each organ's qi collects; they are used both to treat that organ and, when tender on pressure, to help identify which organ is involved. REN-17's Front-Mu status is the reason a chest point is used for palpitations, anxiety and emotional constraint — those are Pericardium territory in classical theory. Its Back-Shu counterpart is Jue Yin Shu BL-14.
• Hui-Meeting (influential) point of Qi. The eight Hui-Meeting points, set out in the Nan Jing, each govern one tissue or substance across the whole body rather than one channel. REN-17 is assigned qi itself — the broadest assignment in the set. That is why it appears in prescriptions for qi stagnation and qi deficiency wherever they sit, not only in the chest.
• Point of the Sea of Qi. The classical Four Seas scheme places the sea of qi in the chest, with REN-17 at its front and Da Zhui DU-14 and Ya Men DU-15 at its back. This is the theoretical statement of the same fact the Hui-Meeting classification makes practically.

Is Qi Hai REN-06 the "Sea of Qi" point, or is REN-17?

Both names are correct, and they refer to different things — a point of genuine confusion worth settling. Qi Hai REN-06 on the lower abdomen is named "Sea of Qi", and it is the great point for tonifying original qi in the lower burner. But the classical Sea of Qi points of the Four Seas scheme are the ones listed above, and Sacred Lotus sources & references carry that classification on REN-17, DU-14, DU-15 and ST-09 — not on REN-06. The tradition holds a sea of qi in the chest, governed by REN-17, and a reservoir of original qi below the navel, named Qi Hai. A reader searching for "the sea of qi point" may want either; both are held here, on separate pages.

Is there research on REN-17 Shan Zhong?

REN-17 is one of the few points with genuinely point-specific human research, including a trial that tested it against its immediate neighbour — the strongest design available for asking whether a specific point does anything specific.

• The neighbour-controlled autonomic trial. In a crossover study of 14 healthy men, single instantaneous epifascial needle stimulation was applied on separate days at Danzhong CV-17 and at Zhongting CV-16, the point one rib space below it, without producing the de qi sensation. Stimulation at CV-17 — but not at CV-16 — lowered heart rate and increased the high-frequency component of heart rate variability, an index of cardiac vagal activity (both P = 0.01), while the sympathetic index changed at neither point. The authors argued the result could not be explained as a nonspecific or placebo effect, since the two points were indistinguishable to the participant (Kurono Y et al., Auton Neurosci 2011;161(1–2):116–20, PMID 21216208, DOI 10.1016/j.autneu.2010.12.003). It is a small study, but it is the right shape: two adjacent points, one difference. Zhong Ting REN-16, the control point, is held here on its own page.
• Lactation. A single-blind randomised multicentre study across three Beijing hospitals allocated 276 women with postpartum insufficient lactation to acupuncture at Tanzhong CV-17 alone or to a traditional herbal decoction, measuring breast engorgement, milk volume, prolactin, neonatal weight, feeding and crying. Both groups improved significantly with no significant difference between them (Zhongguo Zhen Jiu 2008;28(5):317–20, PMID 18652318). The comparator was an active treatment rather than placebo, so this shows equivalence to an established option rather than superiority over none — but it is a large, multicentre trial of this single point, which is rare. A later systematic review and meta-analysis of traditional Chinese medicine interventions for postpartum lactation examined the therapies and the points used across the field (Heliyon 2024;10(6):e27154, PMID 38524574, DOI 10.1016/j.heliyon.2024.e27154), and a nursing review reached broadly supportive but cautious conclusions about acupressure for lactation specifically (MCN Am J Matern Child Nurs 2022;47(6):345–352, PMID 36227074, DOI 10.1097/NMC.0000000000000866).
• Point-property measurement. An infrared study compared the surface radiation spectrum at Danzhong CV-17 in women with hyperplasia of the mammary glands against controls, part of a small literature testing whether points differ measurably from surrounding skin in disease (Zhongguo Zhen Jiu 2008;28(7):499–502, PMID 18678162).
• Hiccup. A clinical report describes needling Tian Tu REN-22 with pressure applied at Danzhong CV-17 in 26 cancer patients with intractable hiccup (Zhongguo Zhen Jiu 2014;34(8):746, PMID 25335246). This is an uncontrolled case series of a two-point protocol and is recorded here as documented clinical use, not as evidence of effect.

What is missing should be said plainly: there is no large, well-powered, sham-controlled randomised trial isolating REN-17 for chest tightness, asthma or palpitations, despite these being its principal traditional uses. The autonomic and lactation work above is the best that exists, and both are modest in size.

How does REN-17 compare with the points around it?

Zhong Ting REN-16 lies one rib space below on the same midline and shares the same local actions — it is the control point in the autonomic trial above, and it did not produce the same effect. Yu Tang REN-18, Zi Gong REN-19 and Hua Gai REN-20 continue up the breastbone; all three share REN-17's territory and its transverse-only needling rule, but none carries a special-point classification, and REN-17 is chosen over them in almost every case. Tian Tu REN-22, in the suprasternal notch, shares the descending-qi and throat actions but lies above the bone rather than on it and carries its own deep-needling caution. Ru Gen ST-18 beneath the breast is the local breast point REN-17 is most often paired with. Zhong Fu LU-01, the Front-Mu of the Lungs on the upper chest, is the point to choose when the target is the Lung organ rather than the qi of the chest as a whole. And Nei Guan P-06 at the wrist is REN-17's distal partner — the Pericardium channel's own point for the chest, reached from a safe distance.

Source: Deadman & Al-Khafaji, A Manual of Acupuncture (p. 517); Chinese Acupuncture & Moxibustion (p. 239); Sacred Lotus sources & references (REN-17 record; Hui-Meeting, Front-Mu and Sea of Qi point sets queried in full); Nan Jing, Difficulty 45; PMID 21216208; PMID 18652318; PMID 38524574; PMID 36227074; PMID 18678162; PMID 25335246; PMID 33068361 — each verified resolvable and checked for retraction status before citation; cross-referenced against multiple online sources.