BL-28 (Pang Guang Shu) Bladder Shu

What does BL-28 Pang Guang Shu do?

Pang Guang Shu BL-28 is the Back-Shu point of the Bladder — the point on the back through which the tradition reaches the bladder itself — and its recorded work is to regulate the Bladder, to clear damp-heat from the lower burner, to dispel stagnation and resolve masses, and to benefit the lumbar region and legs. Sacred Lotus sources & references record that Back-Shu classification and those four actions directly. It sits on the sacrum, one and a half cun either side of the midline, level with the second posterior sacral foramen. The classification is the whole explanation of the point: of the hundreds of points on the body, twelve are designated as the direct back access to an organ, and this is the one assigned to the bladder.

• Regulates the Bladder — the defining action and the reason the point exists. "Regulates" is the right word and is worth taking literally: the recorded indications run in both directions, covering retention of urine and difficult urination on one side and frequent urination and bed-wetting on the other. The tradition does not claim the point drives urination one way; it claims it restores the organ's normal rhythm, and the modern measurement described under research tests exactly that claim.
• Clears damp-heat from the lower burner — the pattern-based action behind its use in hot, burning, urgent, cloudy urination and in the discharge complaints. Damp-heat in the lower burner (xia jiao, the lowest of the three divisions of the trunk) is the classical pattern that maps most closely onto what modern medicine calls a urinary tract infection, and it is the pattern this point is most often selected for.
• Dispels stagnation and resolves masses — the least familiar of the four and the reason the point appears in the older literature for abdominal lumps and hard swellings low in the belly. It is a classical-record action rather than one with any modern evidence behind it, and is recorded here as such.
• Benefits the lumbar region and legs — the local and structural action shared by the whole run of points down the lower back and sacrum. Stiffness and pain of the low back and sacrum, and pain running into the leg, are among its most common uses in modern practice, and for many practitioners this is what BL-28 is reached for far more often than anything urinary.

What is a Back-Shu point, and which twelve does this site hold?

The Back-Shu points are the twelve points on the inner Bladder line, one and a half cun either side of the spine, each of which the tradition assigns to one internal organ. Sacred Lotus sources & references hold all twelve, and the set was queried directly rather than recalled — it returns exactly twelve, and BL-28 is one of them. They run down the back in the order of the organs, and knowing the run is the fastest way to orient yourself on the whole back:

• BL-13 Fei Shu — Lungs, at T3.
• BL-14 Jue Yin Shu — Pericardium, at T4.
• BL-15 Xin Shu — Heart, at T5.
• BL-18 Gan Shu — Liver, at T9.
• BL-19 Dan Shu — Gall Bladder, at T10.
• BL-20 Pi Shu — Spleen, at T11.
• BL-21 Wei Shu — Stomach, at T12.
• BL-22 San Jiao Shu — San Jiao, at L1.
• BL-23 Shen Shu — Kidneys, at L2.
• BL-25 Da Chang Shu — Large Intestine, at L4.
• BL-27 Xiao Chang Shu — Small Intestine, at the first posterior sacral foramen level.
• BL-28 Pang Guang Shu — Bladder, at the second posterior sacral foramen level. This point, and the lowest of the twelve.

Two things follow from that list that are worth stating explicitly. First, the run is not continuous — BL-16, BL-17, BL-24 and BL-26 sit on the same line at the same spacing but are not organ Back-Shu points. Queried directly, our own records classify BL-24 as the Sea of Qi Shu, named for the abdominal point Qi Hai REN-06, and BL-26 as the Gate of Origin Shu, named for Guan Yuan REN-04; our BL-24 record establishes that gap from its own side. Second, BL-28 is the last of the twelve: below it the inner line continues with Zhong Lu Shu BL-29 and Bai Huan Shu BL-30, which carry shu names but no organ. So BL-28 marks the bottom end of the whole Back-Shu system.

Source: Sacred Lotus sources & references (channel, the Back Shu of the Bladder classification, and the existing action record — reformatted here from a broken bare list run; the complete twelve-point organ Back-Shu set and the BL-24, BL-26, BL-29 and BL-30 records queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 290; Chinese Acupuncture & Moxibustion, p. 181; Ling Shu (Spiritual Pivot), chapter 51, on the transport points of the back; cross-referenced against multiple online sources.

What is BL-28 Pang Guang Shu used for?

Pang Guang Shu BL-28 is used above all for urinary complaints — retention of urine, bed-wetting and frequent urination are the three our own records name first — and after that for the bowel, for menstrual and discharge complaints, and for stiffness and pain of the low back and sacrum. The indications carried in Sacred Lotus sources & references are retention of urine, enuresis, frequent urination, diarrhoea, constipation, and stiffness and pain of the lower back. The standard reference literature sets them out more fully below. These describe traditional use, not proven treatment.

• Retention of urine and difficult urination
• Enuresis (bed-wetting) and involuntary urination
• Frequent and urgent urination
• Burning, painful or cloudy urination
• Incontinence of urine
• Diarrhoea
• Constipation and difficult defecation
• Stiffness and pain of the lower back and sacrum
• Pain and weakness running from the sacrum into the leg
• Coldness, pain and swelling of the genital region
• Vaginal discharge (leucorrhoea)
• Irregular menstruation and lower-abdominal pain
• Nocturnal emission
• Abdominal masses and hard swellings low in the abdomen — the classical indication behind "resolves masses"
• Swelling and pain of the knee and foot, in the classical record

Why the urinary indications run in both directions. A reader meeting the list for the first time will notice that BL-28 is recorded for retention of urine and for frequent urination, which look like opposites. In the classical framing they are not: both are failures of the bladder to hold and release at the right time, and the Back-Shu point is understood to restore the organ's function rather than to push it one way. That is a claim about regulation, and it is exactly the claim the anaesthetised-rat manometry study described under research put to the test — with a result that, to the extent an animal experiment can, supported it.

Source: Sacred Lotus sources & references (existing indication record, reformatted here as a list from a bare comma-run); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 290; Chinese Acupuncture & Moxibustion, p. 181; cross-referenced against multiple online sources.

Where is BL-28 Pang Guang Shu, and how is it used in practice?

Pang Guang Shu lies on the sacrum, about two fingers' width either side of the midline, level with the second of the four paired openings in the back of the sacrum — the same level as the well-known point Ci Liao BL-32, which sits directly over that opening while BL-28 sits inside it, closer to the midline. Sacred Lotus sources & references hold two location records for the point and they agree exactly, both placing it one and a half cun lateral to the midline at the level of the second posterior sacral foramen. There is no discrepancy between them to flag.

The practical consequence of that geography is worth stating because it is the single most useful thing to know about finding the point. The sacrum is a broad triangular bone and its landmarks are palpable through the skin: the two dimples over the back of the pelvis mark the joints between the sacrum and the hip bones, and the second foramen lies just below and inside them. BL-32 is at the foramen; BL-28 is the same level, closer in. In practice the two are often found together and often used together.

Which points is BL-28 combined with?

• With Zhong Ji REN-03 — its Front-Mu counterpart, and the single most important pairing this point has. Queried directly, REN-03 Zhong Ji is classified in our own records as the Front-Mu point of the Bladder; it lies on the midline of the lower abdomen, four cun below the navel and one cun above the pubic bone, directly over the bladder itself. Back-Shu with Front-Mu is the oldest structured pairing in the medicine — the organ approached from behind and from in front at the same time — and at the bladder it is BL-28 with REN-03. Our REN-03 record names BL-28 from its own side.
• With Ci Liao BL-32 and the eight liao points. BL-32 lies at the same level, over the second sacral foramen; BL-31, BL-33 and BL-34 are at the first, third and fourth. All are held here. The sacral group is the standard local territory for bladder and bowel complaints, and BL-28 is frequently needled as part of it rather than alone.
• With Shen Shu BL-23 — the Back-Shu point of the Kidneys, held here, at L2. In the classical account the Kidneys and Bladder are the paired organs of the Water element, and their two Back-Shu points are used together constantly, particularly where urinary complaints are read as weakness rather than heat. This pairing appears in the published literature repeatedly, described under research below.
• With San Yin Jiao SP-06 — the Meeting Point of the Spleen, Liver and Kidney channels on the inner lower leg, held here, and the principal distal point of urinary and gynaecological practice. BL-28 supplies the local element from behind, SP-06 the distal.
• With Yin Ling Quan SP-09 — the He-Sea point of the Spleen at the inner knee, held here, and the tradition's main point for resolving dampness. Where the presentation is damp-heat in the lower burner, SP-09 is the usual distal partner.
• With Qu Gu REN-02, Guan Yuan REN-04, Shui Dao ST-28 and Gui Lai ST-29 — the lower-abdominal points over the bladder and uterus, all held here. ST-29 Gui Lai is recorded in our own data as lying level with Zhong Ji REN-03, so the front-and-back arrangement can be widened from a single midline point to a row.
• With Xiao Chang Shu BL-27 above and Zhong Lu Shu BL-29 below — its immediate neighbours on the same line, both held here. BL-27 is the Back-Shu point of the Small Intestine and the point immediately above; BL-29 carries a shu name but no organ.
• With Wei Zhong BL-40 — behind the knee, held here, and the Command point of the back under the old rule "for disorders of the low back seek Wei Zhong". It is the standard distal partner for the local action of any sacral or lumbar point.

Which twelve Front-Mu points does this site hold?

Sacred Lotus sources & references hold all twelve Front-Mu points, and the set was queried directly rather than recalled — it returns exactly twelve. Where the Back-Shu points line the back, the Front-Mu points are their counterparts on the front of the body, each lying on or near the organ it is named for. Reading the two sets against each other is the fastest way to grasp the structure of the whole system, and BL-28's partner is in it:

• LU-01 Zhong Fu — Lungs (Back-Shu: BL-13).
• REN-17 Shan Zhong — Pericardium (BL-14).
• REN-14 Ju Que — Heart (BL-15).
• LIV-14 Qi Men — Liver (BL-18).
• GB-24 Ri Yue — Gall Bladder (BL-19).
• LIV-13 Zhang Men — Spleen (BL-20).
• REN-12 Zhong Wan — Stomach (BL-21).
• REN-05 Shi Men — San Jiao (BL-22).
• GB-25 Jing Men — Kidneys (BL-23).
• ST-25 Tian Shu — Large Intestine (BL-25).
• REN-04 Guan Yuan — Small Intestine (BL-27).
• REN-03 Zhong Ji — Bladder (BL-28). This point's partner.

Notice what the list shows at a glance: the Front-Mu points are scattered across four different channels and are not in one line, whereas the Back-Shu points are all on one channel in one orderly run. That asymmetry is the reason the back set is easier to learn and the front set has to be memorised organ by organ. Notice too that three of the twelve Front-Mu points — REN-03, REN-04 and REN-05 — sit within two cun of one another on the lower abdomen, belonging to the Bladder, the Small Intestine and the San Jiao respectively, which is why precision matters more on the lower abdomen than almost anywhere else.

Source: Sacred Lotus sources & references (both location records; the complete twelve-point Front-Mu set and the BL-23, BL-27, BL-29, BL-31, BL-32, BL-33, BL-34, BL-40, REN-02, REN-03, REN-04, ST-28, ST-29, SP-06 and SP-09 records queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 290; Chinese Acupuncture & Moxibustion, p. 181; cross-referenced against multiple online sources.

Where is BL-28 located?

• A Manual of Acupuncture (p. 290): 1.5 cun lateral to the midline, at the level of the second posterior sacral foramen.
• Chinese Acupuncture and Moxibustion (p. 181): 1.5 cun lateral to the Governor Vessel, at the level of the second posterior sacral foramen.

How is BL-28 Pang Guang Shu needled, and what lies beneath it?

Stated plainly and in proportion: BL-28 is a low-hazard point. It lies on the back of the sacrum, one and a half cun from the midline at the second foramen level, and the sacrum itself — a broad plate of bone — sits between the needle and the pelvic cavity. The visceral-injury concern that governs the abdominal points and the pneumothorax concern that governs the thoracic points do not apply here. Sacred Lotus sources & references record perpendicular insertion of 0.8 to 1.2 inches with moxibustion applicable. Everything below is recorded as neutral reference data describing what the textbooks and the published anatomical studies document. It is not instruction, this page does not teach technique, and needling is carried out only by a qualified, licensed practitioner.

The angle and depth the texts record

• Sacred Lotus sources & references record perpendicular insertion of 0.8 to 1.2 inches, with moxibustion applicable — the same figure held here for the sacral foramen points BL-31 to BL-34 and for the lumbar Back-Shu points above.
• Deadman & Al-Khafaji (p. 290) and Chinese Acupuncture & Moxibustion (p. 181) record a comparable bounded perpendicular range, with oblique insertion directed medially toward the sacrum also described.
• Moxibustion is recorded as applicable and is common here; the sacrum is one of the regions where warming techniques, including moxa and cupping, are used at least as often as needles.
• For comparison within our own holdings. Queried directly, the thoracic Back-Shu points such as Fei Shu BL-13 carry markedly tighter figures with an explicit oblique direction, because the lung lies beneath them. BL-28 carries a deeper figure because bone and muscle lie beneath it. Depth figures in this literature track what is underneath the point, not the importance of the point.

What actually lies beneath

• The tissue in order. At the second sacral level, one and a half cun from the midline, a perpendicular needle passes through skin and the thoracolumbar fascia into the erector spinae mass where it thins over the sacrum, and then meets the posterior surface of the sacrum itself. On most people the bone is reached within the recorded range.
• The sacrum is the reason this is a safe point. It is a single fused triangular bone forming the back wall of the pelvis. Behind it are muscle and fascia; in front of it are the pelvic organs. A needle at BL-28 is on the wrong side of that bone to reach anything visceral, which is the plain anatomical reason no organ-injury concern is recorded for it.
• The one structure that does matter is nerve. The posterior branches of the sacral spinal nerves emerge through the four posterior sacral foramina. BL-28 lies medial to the second of those, not over it, but the region as a whole is innervated territory and a radiating or electric sensation into the buttock or leg is described in the reference literature at these points. That sensation is a nerve responding, and it is the recorded phenomenon at the sacral group generally.
• Where the caution actually belongs. Deep needling into a sacral foramen with a long needle is a specialist technique with a measurement literature of its own — and it is a technique of the foramen points BL-31 to BL-34, not of BL-28. See the next section, which is precise about this.

The measured evidence — and exactly which points it measured

• The sacral CT study measured the four foramen points, not BL-28, and we say so rather than borrow it. A retrospective study reconstructed 100 prone pelvic CT scans in three dimensions to measure the angle and effective depth of a needle following the axis of each sacral foramen. The points it measured were Shang Liao BL-31, Ci Liao BL-32, Zhong Liao BL-33 and Xia Liao BL-34 — the points that lie over the foramina. Effective depth, defined as the soft tissue over the sacrum plus half the depth of the sacrum, decreased steadily from BL-31 (58.16 ± 12.43 mm) to BL-34 (31.13 ± 10.94 mm), and correlated positively with body mass index but not with sex or weight alone (Zhen Ci Yan Jiu 2017;42(6):537–541, PMID 29318863). BL-28 is not one of the four and has no figure in that paper. It is cited here because it is the best-quantified anatomy of this region and because a reader who has seen those numbers should know they belong to the neighbours.
• Two general facts about depth. Two systematic reviews of the safe-depth literature — 33 studies in the first, 47 in the second, by MRI, CT, ultrasound and cadaveric dissection — both concluded that measured depths for the same point vary greatly between subject groups and measuring methods, and that "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). Neither reports a figure for this point.
• Where the serious events of acupuncture actually cluster. Systematic reviews of the Chinese case literature place them over the chest, the abdomen, the neck and the orbit, attributed chiefly to improper technique (He W et al., J Altern Complement Med 2012;18(10):892–901, PMID 22967282; Zhang J et al., Bull World Health Organ 2010;88(12):915–921C, PMID 21124716, PMC2995190). The sacrum is not among them.
• Risk in proportion. A meta-analysis of prospective clinical studies estimated serious adverse events in acupuncture at approximately 1 per 10,000 patients and about 8 per million treatments, with roughly half of all recorded events being bleeding, pain or flare at the needle site (Bäumler P et al., BMJ Open 2021;11:e045961, PMID 34489268).
• Honest limit. No published case report naming BL-28 specifically in connection with any injury was located, and none is asserted. What is documented at this point is a bounded depth in the reference texts and a bone directly beneath it.

Source: Sacred Lotus sources & references (existing needling record and both location records; the BL-13, BL-31, BL-32, BL-33 and BL-34 records queried directly for comparison); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 290; Chinese Acupuncture & Moxibustion, p. 181; PMID 29318863 (measuring BL-31 to BL-34, not BL-28); PMID 21417806; PMID 23935678; PMID 22967282; PMID 21124716 (PMC2995190); PMID 34489268 — each verified resolvable and checked for retraction status before citation.

What does the name Pang Guang Shu mean?

Pang Guang Shu means "Bladder Shu" — pang guang, the urinary bladder, and shu, a transport point. Sacred Lotus sources & references translate it exactly that way. There is no metaphor in this name and no poetry: it is a label. Among the twelve organ Back-Shu points, eleven are named in precisely this pattern — the organ, then shu — and the exception is BL-14 Jue Yin Shu, which names the Pericardium by its channel designation rather than by an organ word. The character shu carries the sense of conveying or transporting, and it names the whole class of points on the inner Bladder line where something is understood to be conveyed to the body surface.

There is a small point of clarity worth making, because it catches readers out. The Bladder channel is the longest channel on the body, running from the inner corner of the eye over the head, down both sides of the back and the whole length of the leg to the little toe — sixty-seven points. The Bladder organ is a small sac in the pelvis. The channel is named after the organ but most of its points have nothing to do with urination; almost all the Back-Shu points on it belong to other organs entirely. BL-28 is the one point on the Bladder channel that is the Bladder organ's own back access, which is a narrower and more specific claim than the channel's name might suggest.

Why does it matter that BL-28 is a Back-Shu point?

Because the Back-Shu points are the tradition's most direct structural claim about how a point on the surface relates to an organ inside — and BL-28 is the lowest and last of the twelve. The idea is set out in the Ling Shu: qi from each of the internal organs is said to be transported to a specific site on the back, and needling or pressing that site reaches the organ. Two practical consequences follow, and both are recorded in the classical literature. First, the Back-Shu point is used to treat its organ. Second, tenderness, tension or change at the Back-Shu point is used as a sign in assessing its organ — the point is read as well as needled. That second use is the reason the modern measurement literature described below has bothered to take instruments to these points at all.

The natural partner of a Back-Shu point is its Front-Mu point, and the twelve pairs are set out in full under practice above. For BL-28 that partner is Zhong Ji REN-03, and the pairing is unusually literal: REN-03 lies directly over the bladder on the lower abdomen while BL-28 lies behind it on the sacrum. Front and back, one organ.

How is BL-28 different from the points around it?

Xiao Chang Shu BL-27 lies one level above, at the first sacral foramen level, and is the Back-Shu point of the Small Intestine — the eleventh of the twelve, with BL-28 the twelfth. Zhong Lu Shu BL-29 lies one level below, at the third foramen level, and Bai Huan Shu BL-30 below that at the fourth; queried directly, both carry shu names in our own records but neither is an organ Back-Shu point, which is why the Back-Shu run ends at BL-28. Ci Liao BL-32 sits at the same level as BL-28 but further out, directly over the second sacral foramen, and is the most-used point of the sacrum; our BL-32 record notes the relationship from its own side and is explicit that BL-32 is not a Back-Shu point. Bao Huang BL-53 lies three cun out on the outer Bladder line at the second sacral level — the outer-line companion at BL-28's own level. Da Chang Shu BL-25 at L4 and Guan Yuan Shu BL-26 at L5 are the points above on the lumbar spine. All of these are held in this library and all were queried.

Is there research on BL-28 Pang Guang Shu?

Yes — and unusually for a Back-Shu point, some of it names Pangguangshu BL-28 explicitly and measures something at it, rather than merely including it in a prescription. It is a literature of animal physiology, small clinical series and acupoint-frequency reviews rather than of large trials of the point itself, and that is how it is presented here.

• Bladder pressure measured directly, with BL-28 among the points tested — the study that most closely tests the point's traditional claim. Twenty anaesthetised Sprague-Dawley rats had bladder pressure recorded through a balloon in the bladder while a needle was inserted 4 mm and manually rotated for one minute at each of six points in turn: REN-01, Zhongji REN-03, Pangguangshu BL-28, Ciliao BL-32, REN-02 and Shenshu BL-23. The finding was two-directional: when the bladder was in an active state, stimulation at REN-01, REN-03, BL-28, BL-32 or REN-02 inhibited bladder motility (P < 0.01); when the bladder was static, stimulation at any of those points, and at BL-23, increased motility (P < 0.01). The authors framed this as a dual, state-dependent effect of points that share spinal segmental innervation with the bladder (Qin Q et al., BMC Complement Altern Med 2015;15:267, PMID 26253168, PMC4529689). Its limits are severe and should be stated: anaesthetised rats, a single one-minute stimulation, a pressure measurement rather than any clinical outcome, and no human counterpart. It is included because it is a measurement made at this point by name, and because it addresses head-on the apparent contradiction in BL-28's indication list, where retention and frequency sit side by side.
• A clinical series naming BL-28, and being honest about what it showed. Fifty-eight women prone to recurrent uncomplicated cystitis received individualised acupuncture twice weekly for four weeks and were followed for six months, with residual urine measured by portable ultrasound and autonomic activity by skin conductance. Pangguangshu BL-28 was among the main points used in every one of the three pattern groups identified — Kidney qi/yang deficiency, Liver qi stagnation and Spleen qi/yang deficiency. The result the paper reports, however, belongs to a different pair: the combination of Shen Shu BL-23 with Tai Xi KI-03, used in 16 women, was associated with symptomatic episodes reduced to a third compared with the 42 women in whom it was not used (3/16 versus 28/42, P < 0.05), and BL-23 application correlated with reduced residual urine. The authors also concluded that SP-06 may be less indicated than previously assumed in this group (Alraek T et al., Chin J Integr Med 2016;22(7):510–517, PMID 25491541). BL-28 was used throughout and no separate effect is attributed to it; that is the accurate reading.
• A small stroke-rehabilitation series using BL-28 by name. Stroke inpatients with incomplete bladder emptying — post-void residual over 100 mL on two consecutive days — received electroacupuncture at 1 Hz for 15 minutes at San Yin Jiao SP-06, Ci Liao BL-32 and Pangguangshu BL-28, ten sessions over two weeks. Nine of 49 patients had incomplete emptying and seven were treated; increased spontaneous voiding volume and decreased post-void residual were reported after the ten sessions (Yu KW et al., Clin Interv Aging 2012;7:469–474, PMID 23152677, PMC3496194). Seven patients, no control group, no blinding — it is a preliminary observation and the authors describe it as one.
• Surface temperature measured at BL-28 by name. Infrared thermography compared 50 patients with low back pain from lumbar disc herniation against 45 healthy subjects, measuring bilateral temperature at BL-22, BL-23, BL-24, BL-25, BL-26, BL-27 and BL-28. Left-right differences were greater in patients than controls at several of those levels; comparing affected with unaffected side within the patient group, however, the elevation reached significance only at BL-23 and BL-25, and the authors concluded that those two showed relative specificity (Yuan X et al., Zhongguo Zhen Jiu 2024;44(4):423–427, PMID 38621730). BL-28 was measured and was not among the two that showed the effect. A note on that paper's vocabulary: it describes all seven points as "back-shu points", where our own data classify BL-23, BL-25, BL-27 and BL-28 as organ Back-Shu points, BL-22 as the San Jiao Shu, and BL-24 and BL-26 as named for abdominal points instead. The looser usage is common in the literature and is flagged so a reader is not misled.
• How often BL-28 is chosen, measured across a body of literature. A systematic review of acupoint selection in acupuncture for benign prostatic hyperplasia screened 270 articles and included 85, identifying 61 points in use. Pangguangshu BL-28 was among the ten highest-frequency points, alongside REN-04, REN-03, SP-06, REN-06, BL-23, ST-28, SP-09, REN-02 and BL-32, with the Conception Vessel, Bladder and Spleen channels predominating (Guo C et al., Medicine (Baltimore) 2025;104(32):e43802, PMID 40797416, PMC12338299). This measures practice, not effect, and the authors say plainly that rigorous trials are still needed. What it establishes is that BL-28 is genuinely a first-rank choice in this territory rather than a textbook relic — and it is notable that its own Front-Mu partner REN-03 sits beside it near the top of the same list.
• An older case series. A report of 36 cases of urinary retention treated by acupuncture, in which BL-28 is among the points named, is held in the literature (J Tradit Chin Med 2008;28(2), PMID 18652110). It is an uncontrolled case series from a single centre and carries the limits of that design.
• What is not here. There is no randomised controlled trial of BL-28 on its own, no sham-controlled study of it, and no imaging or cadaveric measurement at this point. Its standing rests on the classical Back-Shu doctrine, on the reference literature, and on its consistent appearance in multi-point protocols. That is stated flatly rather than dressed up.

A point-code caution, recorded because it was met while assembling this. Searching the literature for this point by its code alone is useless — a plain search for the string "BL 28" returns tens of thousands of records across the whole of biology, because the characters match ordinary text. Searching the pinyin "Pangguangshu" returns a small, clean and readable set, and every record considered for this page was read rather than counted.

Source: Sacred Lotus sources & references (name, translation, channel, the Back Shu of the Bladder classification, the complete twelve-point Back-Shu and twelve-point Front-Mu sets, and the BL-23, BL-24, BL-25, BL-26, BL-27, BL-29, BL-30, BL-32, BL-53 and REN-03 records queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 290; Chinese Acupuncture & Moxibustion, p. 181; Ling Shu (Spiritual Pivot), chapter 51, on the transport points of the back; PMID 26253168 (PMC4529689); PMID 25491541; PMID 23152677 (PMC3496194); PMID 38621730; PMID 40797416 (PMC12338299); PMID 18652110 — each verified resolvable and checked for retraction status before citation; cross-referenced against multiple online sources.