BL-18 (Gan Shu) Liver Shu

What does BL-18 Gan Shu do?

Gan Shu BL-18 is the Back-Shu point of the Liver — the place on the back where the Liver's qi is said to infuse the body surface — and it is the principal point of the back for the Liver in all its aspects: its qi, its blood, its wind and its heat. Sacred Lotus sources & references record that classification directly, and it is the fact that organises everything else about the point. Where a treatment intends to reach the Liver from the back, BL-18 is the point that does it.

• Spreads Liver qi — the defining action, recorded first in our own action record. The Liver in classical theory governs the free and smooth movement of qi through the body, and BL-18 is used where that movement is constrained: hypochondriac distension and pain, irritability, a tight chest, sighing, and the digestive disturbance the tradition attributes to constrained Liver qi overrunning the Stomach.
• Regulates and nourishes Liver blood — the second recorded action, and the one that distinguishes BL-18 from most other Liver points. The Liver is said to store the blood, and BL-18 is used both where blood is deficient — dry eyes, blurred vision, scanty menstruation, numbness and cramp — and where it is stagnant or moving wrongly, which is the reasoning behind its recorded indications for coughing or vomiting blood and for nosebleed.
• Pacifies wind — for the tremor, spasm, convulsion, dizziness and rigidity that classical theory attributes to Liver wind, and in the classical management of windstroke and epilepsy. Internal wind is a Liver phenomenon in this system, and the Liver's Back-Shu point is one of the standard places to address it.
• Cools fire and clears damp-heat — the recorded basis for its long-standing use in jaundice, in bitter taste in the mouth, and in the red, painful, hot presentations the tradition places with the Liver and Gall Bladder. BL-19 Dan Shu, the Gall Bladder's Back-Shu point one level below, is its constant partner in this.
• Benefits the eyes and the sinews — the classical correspondences, and the reason a point on the mid-back carries a substantial list of eye indications. The Liver is said to open into the eyes and to govern the sinews; night blindness, blurred vision, dry or red eyes, and cramping and contracture of the tendons all follow from that reasoning.

Why does the Back-Shu classification matter?

The Back-Shu points are the tradition's most direct route to an internal organ. Each is understood as the place where that organ's qi infuses the back, which gives them two roles: they are used to treat the organ, particularly in chronic and deficient conditions, and they are palpated in diagnosis, since tenderness, a sunken feeling or a change in the tissue at a Back-Shu point is read as a sign that its organ is involved. Because the Liver is the organ classical theory holds responsible for the smooth movement of qi throughout the body, its Back-Shu point has an unusually wide reach — into the emotions, the eyes, the sinews, the menstrual cycle and the digestion alike.

Source: Sacred Lotus sources & references (existing action record; Back-Shu classification queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 275); Chinese Acupuncture & Moxibustion (p. 179); cross-referenced against multiple online sources.

What is BL-18 Gan Shu used for?

Gan Shu BL-18 is used for the eye, hypochondriac, emotional and blood complaints that classical theory attributes to the Liver — jaundice, pain under the ribs, blurred and dim vision, night blindness, and irritability. The indications carried in Sacred Lotus sources & references are listed below alongside those set out in the standard reference literature. They describe traditional use, not proven treatment, and this is a thoracic point with the pneumothorax considerations set out in full under needling.

• Jaundice
• Pain and distension in the hypochondriac region
• Redness, pain and swelling of the eyes
• Blurring of vision and dimness of sight
• Night blindness
• Dry eyes
• Mental-emotional disturbance and irritability
• Epilepsy
• Backache and stiffness of the upper and mid back
• Coughing or vomiting of blood
• Nosebleed
• Dizziness and vertigo
• Cramp, spasm and contracture of the sinews
• Irregular or scanty menstruation
• Bitter taste in the mouth

Source: Sacred Lotus sources & references (existing indication record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 275); Chinese Acupuncture & Moxibustion (p. 179).

Where is BL-18 Gan Shu, and how is it used in practice?

Gan Shu lies on the mid-back, one and a half cun either side of the midline, level with the lower border of the spinous process of the ninth thoracic vertebra — that is, level with Jin Suo DU-08 on the spine itself. Sacred Lotus sources & references give it in both terms. It is a bilateral point, needled on both sides, and it sits in the muscle mass beside the spine at the level where the back begins to narrow below the shoulder blades.

In practice BL-18 is used constantly and in two quite different registers. As a Back-Shu point it is reached for in any chronic Liver pattern — constrained qi, deficient blood, rising yang, damp-heat — usually together with its Front-Mu point on the chest and with a distal Liver-channel point. And as a local point it is used for the mid-back itself. It is also one of the most frequently palpated points in diagnosis: tenderness at BL-18 is a routine finding practitioners take as pointing toward the Liver.

Which points is BL-18 combined with?

• With Qi Men LIV-14 — the Front-Mu point of the Liver, on the chest below the nipple. Back-Shu with Front-Mu is the classical Shu-Mu pairing for reaching an organ from front and back at once, and this is its Liver instance. Both points are held in this library, and both are intercostal or thoracic points carrying the same family of depth considerations.
• With Tai Chong LIV-03 — the Yuan-Source point of the Liver channel, on the foot. Back-Shu with Yuan-Source is the classical pairing for supplementing an organ, and LIV-03 is BL-18's standing distal partner.
• With Dan Shu BL-19 — the Gall Bladder's Back-Shu point one level below at T10. The Liver and Gall Bladder are a paired organ couple and their two Shu points are used together almost as a unit, particularly for jaundice and damp-heat.
• With Shen Shu BL-23 — the Kidney's Back-Shu point in the lower back, for the pattern the tradition calls Liver and Kidney deficiency, which underlies a great deal of eye, menstrual and sinew pathology. The pairing is one of the most-used in the whole Back-Shu group.
• With Ge Shu BL-17 — the Hui-Meeting Point of Blood, one level above at T7. BL-17 with BL-18 is the classical combination for blood: BL-17 for blood as a substance, BL-18 for the organ that stores it.
• With Guang Ming GB-37 and Jing Ming BL-01 — for eye disorders, joining the Liver's Back-Shu point to the Gall Bladder channel's "Bright Light" Luo-Connecting point and to the point at the inner canthus.
• With Yang Ling Quan GB-34 — the Hui-Meeting Point of the Sinews and the He-Sea point of the Gall Bladder channel. The pairing is used for hypochondriac pain, for contracture, and it is the combination tested in the animal liver research described under notes.
• With Hun Men BL-47 — "Hun Gate", on the outer Bladder line three cun lateral at the same T9 level, the outer companion of BL-18 and the point associated with the hun, the ethereal soul the Liver is said to house.

Where does BL-18 sit among the Back-Shu points?

The Back-Shu points run down the inner Bladder line, one and a half cun either side of the spine, one for each organ, in roughly the order the organs sit in the trunk. Sacred Lotus sources & references hold the complete set of twelve, and they are worth seeing together because the arrangement is the point:

• Fei Shu BL-13 — Lungs
• Jue Yin Shu BL-14 — Pericardium
• Xin Shu BL-15 — Heart
• Gan Shu BL-18 — Liver
• Dan Shu BL-19 — Gallbladder
• Pi Shu BL-20 — Spleen
• Wei Shu BL-21 — Stomach
• San Jiao Shu BL-22 — San Jiao
• Shen Shu BL-23 — Kidneys
• Da Chang Shu BL-25 — Large Intestine
• Xiao Chang Shu BL-27 — Small Intestine
• Pang Guang Shu BL-28 — Bladder

Each Back-Shu point pairs with its organ's Front-Mu point on the front of the trunk. The Liver's Front-Mu is Qi Men LIV-14, on the chest — one of the few Front-Mu points that sits on its own organ's channel, which is not the rule: our own records show the Kidneys' Front-Mu on the Gall Bladder channel at Jing Men GB-25, the Spleen's at Zhang Men LIV-13 on the Liver channel, and the Pericardium's at Shan Zhong REN-17 on the Conception Vessel. BL-18 is among the four or five most-used of the twelve, alongside BL-13, BL-20 and BL-23, because the Liver patterns it addresses are among the most commonly diagnosed in modern practice.

Source: Sacred Lotus sources & references (BL-18 record; the full twelve-point Back-Shu set and the twelve Front-Mu points queried directly, and reproduced here identically to the set carried in the BL-23 record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 275); Chinese Acupuncture & Moxibustion (p. 179); cross-referenced against multiple online sources.

Where is BL-18 located?

• A Manual of Acupuncture (p. 275): 1.5 cun lateral to the lower border of the spinous process of the ninth thoracic vertebra (T9).
• Chinese Acupuncture and Moxibustion (p. 179): 1.5 cun lateral to Jinsuo (DU-8), at the level of the lower border of the spinous process of the ninth thoracic vertebra.

How is BL-18 Gan Shu needled, and what lies beneath it?

Stated plainly: BL-18 is a thoracic point at the level of the ninth thoracic vertebra, one and a half cun from the midline, and the standard references do not record a perpendicular insertion here. Our own record specifies oblique insertion of 0.5 to 0.7 inch, with moxibustion applicable — and the angle is the safety instruction, not a stylistic detail. The pleura, the membrane enclosing the lung, descends posteriorly well below the level of BL-18, and pneumothorax is the documented complication of needling points in this band. Everything below is neutral reference data describing what the textbooks and the published anatomical studies 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 oblique insertion of 0.5 to 0.7 inch, with moxibustion applicable. That is one of the shallower figures held here for any point on the trunk, and it is close to the 0.3–0.5 inch our own records give for GB-21 over the apex of the lung and for LIV-14 in the intercostal space.
• Deadman & Al-Khafaji (p. 275) and Chinese Acupuncture & Moxibustion (p. 179) record oblique insertion — angled medially toward the spine, or obliquely inferior — in a comparable range at the thoracic Back-Shu points, and both attach an explicit caution against deep perpendicular insertion because of the lung beneath.
• Why oblique. The reason given in the reference literature is geometric: a needle angled toward the spine or along the surface travels through the erector spinae muscle mass beside the vertebra, whereas a perpendicular needle at the same point travels toward the intercostal space and the pleura behind it. The recorded angle exists to keep the needle in muscle.
• Moxibustion is recorded as applicable and carries none of the depth considerations that needling does.

The measured anatomy — what has been quantified, and what has not

• Honest limit, stated first. No imaging study measuring a safe needling depth at BL-18 specifically could be located. The thoracic Back-Shu points have not been measured in the way the shoulder, chest, nape and lumbar points have. Rather than borrow a figure measured elsewhere and attach it to this point, what is recorded here is the bounded depth and specified angle the reference texts give, the systematic review that did examine this point, and the measured anatomy of the surrounding region — with each measurement attributed to the point at which it was actually made.
• The one systematic review that examined BL-18 directly. A PRISMA-compliant systematic review searched six databases to their inception and included 115 articles describing the anatomical structures and needling method of the Back-Shu points BL-18, BL-20 and BL-22. Of these, 108 described the depth or method, 96 described depth, 86 described angle, 74 described both, and 79 described the target muscles and anatomical structure. The review's contribution is that it collates and analyses what the source literature actually specifies about angle, depth and the muscle layer aimed at, for these three points in particular; its own conclusion is that few studies have assessed how to stimulate these points effectively and that more work is needed (Cho Y et al., Medicine (Baltimore) 2022;101(43):e29878, PMID 36316824, PMC9622668, DOI 10.1097/MD.0000000000029878). It is a review of the descriptive literature, not a direct imaging measurement — an important distinction, and one worth stating rather than glossing.
• Where the pleura actually reaches. The pleural cavity extends considerably further down at the back than most people expect: posteriorly it descends to roughly the level of the twelfth rib, so the ninth thoracic vertebral level at which BL-18 sits is well within the band in which lung and pleura lie deep to the back muscles. This is the plain anatomical reason the oblique angle is recorded here and not at the lumbar Shu points below.
• What measurement at nearby points establishes. The margins in this general region have been measured directly at other points and they are small. Ultrasound in 101 adults measured the depth from the skin at Jian Jing GB-21 to the pleural line at the lung apex at 17.4 mm in men and 14.6 mm in women, increasing with weight, height and body mass index (Lin S-K et al., J Acupunct Meridian Stud 2018;11(6):355–60, PMID 29936338). A CT study of 120 adults measured skin-to-pleura distances at chest points and found significant differences between body-size groups (PMID 1338010), and a study of chest CT in patients aged 4 to 18 found the margins smallest in children and significantly different by sex, age, weight and body mass index (PMID 26457105). None of these three measured BL-18. They are cited for the principle they establish about the thoracic band — that the distance to the pleura is short and varies with the body — and no figure from them is attributed to this point.
• Comparison with a Shu point that has been measured. By way of contrast, the lumbar Shu points were measured directly: an MRI study of 61 subjects measured the dangerous and safe depths of perpendicular and oblique needling at the kidney-region points including Shen Shu BL-23, and found both significantly greater in overweight than in moderate-build subjects, and greater in moderate than in underweight subjects (Chen GT et al., Zhongguo Zhen Jiu 2022;42(9):1006–10, PMID 36075596). That study measured BL-21, BL-22, BL-23, BL-50, BL-51 and BL-52 — not BL-18. It is included to show what a point-specific measurement looks like, and to make clear that BL-18 does not yet have one.
• No agreed safe depth exists for any point. Two systematic reviews of the safe-depth literature — 33 studies in the first, 47 in the second, measured by MRI, CT, ultrasound and cadaveric dissection — both concluded that depths measured for the same point differ greatly between subject groups and measuring methods, and that the definition of "safe depth" has never been standardised (J Altern Complement Med 2011;17(3):199–206, PMID 21417806; Evid Based Complement Alternat Med 2013;2013:740508, PMID 23935678).

What is documented, and how often

Pneumothorax — a punctured lung — is the second most frequently reported serious adverse event in acupuncture. A systematic review of the Chinese case-report literature from 1956 to 2010 identified 1,038 adverse-event cases across 167 articles, of which 307 were pneumothorax, behind only fainting; thirty-five deaths were recorded across the whole series, and the authors attributed the events chiefly to improper technique, concluding that most were avoidable through standardised training (He W et al., J Altern Complement Med 2012;18(10):892–901, PMID 22967282). Fatal cases exist: an autopsy report describes bilateral pneumothoraces immediately following electroacupuncture, the authors noting that electrical pulses and the muscle contraction they cause may draw needles deeper than the depth at which they were inserted (J Forensic Sci 2022;67(1):377–383, PMID 34435369). A case in the emergency-medicine literature describes pneumothorax presenting the day after needling for back pain, diagnosed on point-of-care ultrasound (Cureus 2021;13(3):e14207, PMID 33948398, PMC8086747).

Delayed presentation. The reference literature notes that a pneumothorax following needling over the back or thorax may not declare itself immediately, presenting hours later with sudden chest pain, breathlessness or a persistent dry cough. It is a medical emergency requiring immediate assessment.

Liver injury. BL-18 is on the back and the caution here is the pleura rather than the liver — but it is worth recording, since this is the Liver's point, that direct injury to the liver from an acupuncture needle is documented, though rare: a radiology case report describes acute haemoperitoneum from direct liver injury caused by acupuncture (J Radiol Case Rep 2023;17(8):15–20, PMID 37654899, PMC10435255). That injury arose from needling over the liver on the front of the trunk, the territory of LIV-14, not from BL-18.

The risk in proportion

A meta-analysis of prospective clinical studies estimated serious adverse events from acupuncture at approximately 1 per 10,000 patients and around 8 per million treatments, with about half of all recorded events being bleeding, pain or flare at the needle site, placing acupuncture among the safer treatments in medicine (Bäumler P et al., BMJ Open 2021;11:e045961, PMID 34489268). Both things are true at once: the absolute risk is small, and it concentrates in the points that overlie the pleura. BL-18 is one of them, and the shallow oblique angle recorded for it is the reason it does not appear in the case literature.

Source: Sacred Lotus sources & references (existing needling record, including its specification of oblique insertion); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 275); Chinese Acupuncture & Moxibustion (p. 179); PMID 36316824 (PMC9622668); PMID 29936338; PMID 1338010; PMID 26457105; PMID 36075596; PMID 21417806; PMID 23935678; PMID 22967282; PMID 34435369; PMID 33948398 (PMC8086747); PMID 37654899 (PMC10435255); PMID 34489268 — each verified resolvable and checked for retraction status before citation.

What does the name Gan Shu mean?

Gan Shu means "Liver Shu" — gan, the Liver, and shu, a transport point. The character shu carries the sense of conveying or transporting, and the Back-Shu points are named for exactly that: the places on the back where each organ's qi is said to be transported to the body surface. Sacred Lotus sources & references translate the name as Liver Shu and classify the point as the Back-Shu of the Liver. Like the other eleven names in the set, it is a description of function rather than a metaphor — which makes the twelve Back-Shu points among the easiest names in acupuncture to learn, and BL-18 among the easiest of all to place once the level is known.

Why is the Liver's Back-Shu point used for the eyes?

Because of a correspondence stated in the earliest layer of the theory: the Liver is said to open into the eyes, and to store the blood that nourishes them. This is why a point on the mid-back carries night blindness, blurred vision, dim sight, dry eyes and red painful eyes among its standing indications — a list that looks incongruous until the correspondence is known, and entirely coherent once it is. The same reasoning runs through the point's other apparently unrelated indications: the Liver governs the sinews, hence cramp and contracture; the Liver stores blood, hence the menstrual indications and the bleeding ones; the Liver governs the free movement of qi, hence the emotional ones. BL-18 is the clearest single illustration on the site of how one organ correspondence generates an entire indication list.

Is there research on BL-18 Gan Shu?

BL-18 has a genuine point-specific research literature, but it is preclinical. No randomised controlled trial isolating BL-18 as the tested variable in humans has been identified, and it would be misleading to suggest otherwise. The animal work is interesting for one reason in particular: it clusters, as with the Liver's Front-Mu point LIV-14, around the organ the point is named for.

• Liver protection, preclinical, with a non-point control. Forty rats were randomised to sham surgery, hepatic ischaemia-reperfusion injury, electroacupuncture at bilateral Ganshu BL-18 and Yanglingquan GB-34, or electroacupuncture at non-points 6–8 mm from BL-18, with treatment given before the injury was induced. Serum ALT, AST, TNF-α, IL-6 and HMGB1, the liver injury score and hepatic HMGB1 protein and mRNA all fell in the BL-18/GB-34 group but not in the non-point group (Tan SY et al., Zhen Ci Yan Jiu 2020;45(11):888–94, PMID 33269832, DOI 10.13702/j.1000-0607.200374). The non-point control just millimetres away is what makes this study worth citing — it is a test of point specificity, not merely of needling. It is also, notably, the classical BL-18/GB-34 pairing being tested as a pairing.
• Liver protection against drug injury. A related experiment in 40 mice used acupuncture and moxibustion at Dazhui GV14 with bilateral Ganshu BL-18, Shenshu BL-23 and other points against cisplatin-induced liver injury, reporting reduced hepatocyte apoptosis through an ER-stress signalling pathway (Zhen Ci Yan Jiu 2024;49(7):686–92, PMID 39020486). A multi-point animal protocol, noted for completeness.
• Bone, preclinical. Moxibustion at Ganshu BL-18 and Shenshu BL-23 was studied for effects on the muscle-bone relationship in a rat osteoporosis model (Zhen Ci Yan Jiu 2022;47(7):605–10, PMID 35880277) — the classical Liver-and-Kidney pairing, tested as a pairing.
• Where BL-18 ranks in human practice. A PRISMA-compliant systematic review and meta-analysis of acupoint thread-embedding for non-alcoholic fatty liver disease with abnormal transaminases included fifteen studies and 1,349 patients, and found BL-18 Ganshu the most frequently used point across the whole body of trials (Medicine (Baltimore) 2020;99(3):e18775, PMID 32011470, PMC7220490). The review's own conclusion is cautious about the quality of the included evidence, and the finding to take from it is about point selection rather than about efficacy. Separately, a randomised trial of electroacupuncture at the Back-Shu points of the five zang — Ganshu BL-18, Xinshu BL-15, Pishu BL-20, Feishu BL-13 and Shenshu BL-23 — in 72 patients with chronic fatigue syndrome reported improvement in physical and mental fatigue scores (Zhongguo Zhen Jiu 2022;42(11):1205–10, PMID 36397215); that is a five-point protocol and its result belongs to the protocol.
• Anatomy. The systematic review of the anatomical structures and needling method of BL-18, BL-20 and BL-22 described under needling (PMID 36316824, PMC9622668) is the one substantial piece of work that examines this point's anatomy in its own right.

What is missing should be said plainly: there is no controlled clinical trial isolating BL-18 for eye disorders, hypochondriac pain, jaundice, menstrual complaints or emotional disturbance, and no imaging study has measured a safe needling depth at this point. The large modern literature that includes BL-18 among its points — for fatty liver, depression, insomnia, dry eye, osteoporosis and much else — is a literature about protocols, and this site does not present it as though it were about this point. The animal liver work is the closest thing to point-specific evidence and it is animal work.

How does BL-18 compare with the points around it?

Qi Men LIV-14 is BL-18's front-of-body counterpart, the Front-Mu point of the Liver on the chest below the nipple, and the two together form the classical Shu-Mu pair for this organ; where BL-18 is reached for chronic and deficient Liver patterns, LIV-14 is the more diagnostic of the two and the point with the deeper classical pedigree, being the point named most often in the Shang Han Lun. Dan Shu BL-19 lies one level below at T10 and is the Gall Bladder's Back-Shu point — the paired organ, and BL-18's constant companion in damp-heat and jaundice. Ge Shu BL-17, one level above at T7, is the Hui-Meeting Point of Blood and the natural partner when blood rather than the organ is the target. Pi Shu BL-20 at T11 is the Spleen's, the point most often paired with BL-18 where constrained Liver qi is held to have overrun the digestion. Hun Men BL-47 sits three cun lateral at the same T9 level on the outer Bladder line — the outer companion of BL-18, named for the hun, the ethereal soul the Liver is said to house, and used where the Liver's disturbance is read as a disturbance of the spirit rather than of the body. Jin Suo DU-08 lies directly medial on the midline at the same level. And distally, Tai Chong LIV-03 on the foot is BL-18's standing partner, the Yuan-Source point of the Liver channel, reached for whenever the Back-Shu point is used. All are held in this library.

Source: Sacred Lotus sources & references (name, translation, Back-Shu classification and the neighbouring point records — including the LIV-14 Qi Men record — queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 275); Chinese Acupuncture & Moxibustion (p. 179); PMID 33269832; PMID 39020486; PMID 35880277; PMID 32011470 (PMC7220490); PMID 36397215; PMID 36316824 (PMC9622668) — each verified resolvable and checked for retraction status before citation; cross-referenced against multiple online sources.