BL28 (Páng Guāng Shū, “Bladder Shu”) is the Back-Shu of the Bladder point of the Bladder Meridian. It is located on the lower back, 1.5 cun lateral to the midline, at the level of the second sacral foramen. This corresponds to the space below the spinous process of the second sacral vertebra (S2). The classics locate it below the nineteenth vertebra. It regulates the Bladder and the lower jiao, clears damp-heat from the lower jiao, strengthens the lumbar spine and legs, resolves stagnation and masses.
On the lower back, 1.5 cun lateral to the midline, at the level of the second sacral foramen. This corresponds to the space below the spinous process of the second sacral vertebra (S2). The classics locate it below the nineteenth vertebra.
Perpendicular or slightly oblique insertion towards the midline, 0.8 to 1.2 cun. Deep insertion enters the second posterior sacral foramen.
Regulates the Bladder and the lower jiao, clears damp-heat from the lower jiao, strengthens the lumbar spine and legs, resolves stagnation and masses.
Abdominal pain, hard and knotted accumulations in the abdomen, women's abdominal masses (jia ju), wind-laborfeng lao yao tong, lumbar pain, spinal rigidity and stiffness, difficulty bending and extending the back, inability to bend forward or backward, foot and knee weakness, urinary redness and yellowing, difficult urination, urinary incontinence, dribbling urination, painful urination, diarrhea, constipation, tetanus with heat, back-arching rigidity (opisthotonos), heat with spasms and pulling, sweat that does not come out, cold sensation in the shins, pain and stiffness of the spine, women's red and white vaginal discharge, urinary retention.
As the Back-Shu point of the Bladder, BL28 is a primary point for treating disorders of its related organ and the lower jiao. The classical texts emphasize its role in regulating urination, addressing conditions from difficult, painful, or red urine to incontinence. It is also a key local point for lumbar pain, spinal stiffness, and weakness in the legs, particularly when bending and extending are difficult. Furthermore, its ability to resolve stagnation is highlighted by its use for abdominal masses and accumulations, especially in women.
Classical text; the translation was prepared with AI and is not clinical advice.
《針灸甲乙經》 Zhēnjiǔ Jiǎyǐ Jīng — Systematic Classic of Acupuncture & Moxibustion, c. 256–282 · 卷09 · Source: Wikisource ↗
腰脊痛強引背、少腹，俯仰難，不得仰息，腳痿重，尻不舉，溺赤，腰以下至足清不仁，不可以久坐，膀胱俞主之The text records that BL28 was used for painful stiff lumbar spine pulling on the back and lower abdomen, difficulty bending, inability to breathe lying back, weak heavy legs, inability to raise the buttocks, red urine, cold numbness from the waist to the feet and inability to sit long.
《黃帝明堂灸經》 Huángdì Míngtáng Jiǔjīng — The Yellow Emperor's Bright Hall Moxibustion Classic, Tang · 卷中 · 揹人形第二 · Source: jicheng.tw ↗
膀胱俞 二穴，在第十九椎下兩旁各一寸半陷者中，灸七壯。 主腰脊急強，腰以下酸重，勞損不仁，腹中痛，大便難也The text records that BL28, in the depression 1.5 cun on each side below the nineteenth vertebra, was moxibusted with 7 cones for stiffness of the lumbar spine, aching heaviness below the waist, numbness from overstrain, abdominal pain and difficult defecation.
《針方六集》 Zhēnfāng Liùjí — Six Collections on Needling, Wu Kun, 1618 · 卷之五·紛署集 · 背自第一椎兩旁夾脊各一寸五分下至節凡四十四穴第八 · Source: jicheng.tw ↗
膀胱俞二穴，主風勞脊強腰疼，小便赤澀，遺溺，小腹滿，大便難，足胻拘急，不能屈伸，腳膝無力，陰瘡，女人癥瘕，月事不調The text records that BL28 was used for wind-taxation with stiff spine and low back pain, scanty reddish urine, enuresis, lower abdominal fullness, difficult defecation, cramping of the shins with inability to bend and stretch, weak legs and knees, genital sores, and in women abdominal masses and irregular menstruation.
《醫宗金鑑·刺灸心法要訣》 Yīzōng Jīnjiàn · Cìjiǔ Xīnfǎ Yàojué — Golden Mirror of Medicine: Essential Teachings on Acupuncture & Moxibustion, Wu Qian et al., 1742 · 卷七 · 背部主病針灸要穴歌 · Source: jicheng.tw ↗
膀胱俞治小便難，少腹脹痛不能安，更治腰脊強直痛，艾火多添疾自痊The verse records that BL28 was used for difficult urination and restless distending pain of the lower abdomen, as well as stiff painful lumbar spine, and claims that adding plenty of moxa would let the illness subside.
BL28 is one of 67 points on the Bladder Meridian. Nearby points:
BL28 (Páng Guāng Shū) is located on the lower back, 1.5 cun lateral to the midline, at the level of the second sacral foramen. This corresponds to the space below the spinous process of the second sacral vertebra (S2). The classics locate it below the nineteenth vertebra.
BL28 regulates the Bladder and the lower jiao, clears damp-heat from the lower jiao, strengthens the lumbar spine and legs, resolves stagnation and masses. Common clinical indications include abdominal pain, hard and knotted accumulations in the abdomen, women's abdominal masses (jia ju), wind-laborfeng lao yao tong, lumbar pain, spinal rigidity and stiffness, difficulty bending and extending the back, inability to bend forward or backward, foot and knee weakness, urinary redness and yellowing, difficult urination, urinary incontinence, dribbling urination, painful urination, diarrhea, constipation, tetanus with heat, back-arching rigidity (opisthotonos), heat with spasms and pulling, sweat that does not come out, cold sensation in the shins, pain and stiffness of the spine, women's red and white vaginal discharge, urinary retention.
Perpendicular or slightly oblique insertion towards the midline, 0.8 to 1.2 cun. Deep insertion enters the second posterior sacral foramen.
BL28 is a point on the Bladder Meridian (Zú Tài Yáng Páng Guāng Jīng).