Bladder Meridian
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BL-32
Needle Depth
1.0–2.0 cun
Needle Angle
45° (Oblique), 90° (Perpendicular)
Body Area
Back — Sacral
Location
In the 2nd posterior sacral foramen, about midway between the posterior superior iliac spine (PSIS) and the midline.
Main Actions
- Regulates the Lower Burner and facilitates urination and defecation
- Resolves Dampness and regulates menstruation
- Benefits the lower back and legs
Indications
Enuresis
Diarrhea
Sciatica
Dark Urine
Borborygmi
Leukorrhea
Labor pain
Infertility
Sacral pain
Constipation
Anus prolapse
Painful period
Genitalia pain
Lower back pain
Uterus prolapse
Painful urination
Urinary retention
Urinary difficulty
Lower back numbness
Defecation difficulty
Irregular menstruation
Commentary
'Liao' means crevice, thus BL-31, BL-32, BL-33 and BL-34 are called 'Siliao'(Four crevices) or 'Baliao'(Eight crevice since there are four crevices on each side). They are called so, due to their location in the four sacral foramina.
Shangliao BL-31 (Upper crevice) is at the highest sacral foramina. Ciliao BL-32 (Second crevice) is at the second. Zhongliao BL-33 (Middle crevice) the third, while Xialiao BL-34 (Lower crevice) is the last one.
All these four points share similar actions, but Ciliao BL-32 is the most important one with the widest indication.
First of all, it regulates the Lower Burner and treats urination and defecation Difficulties. Kidney Deficiency is an important underlying pattern for this disorder, which is frequently seen in elderly and weak patients. Typical urinary manifestations include painful and difficult urination, dark and retention of urine as well as enuresis. While intestines related symptoms covers difficult defecation, constipation, borborygmi and diarrhoea.
Furthermore, by removing Dampness from the Lower Burner, it is effective in treating gynecological disorders such as dysmenorrhoea, infertility, irregular menstruation, labor pain and leucorrhoea. BL-32 is especially useful for infertility and painful periods. It can also reduce back pain during labor.
BL-32 is indicated for genital disorders as well, but Xialiao BL-34 has the strongest effect. Typical manifestations are swelling and painful vagina, incessant green vaginal discharge, pain of the testicles and etc.
All these four points benefit the lumbar region, lower back and legs. They remove the Painful Obstructions from the Channel by invigorating the Qi and Blood. Ciliao BL-32 and Zhongliao BL-33 have the most effect on this action.
Finally, BL-32 also promotes the Qi ascending so as to treat anus or Uterus prolapse.
Classical Sources
Huang Di Nei Jing Su Wen (Yellow Emperor's Inner Canon - Basic Questions) - Bone Hollow Theory:
"腰痛不可转摇，引阴卵，刺八髎与痛上，八髎在腰尻八间" - For low back pain that prevents turning or rotating, with pain radiating to the genitals, needle the Eight Liao points at the site of pain. The Eight Liao are located in the eight spaces of the lumbar-sacral region.
Zhen Jiu Jia Yi Jing (Systematic Classic of Acupuncture):
This text first documented Ciliao as an independent point, noting it treats conditions of the lower back, urinary difficulties, and reproductive disorders. It specified needling depth of approximately 2 cun for the sacral foramen points.
Zhen Jiu Da Cheng (Great Compendium of Acupuncture):
"八髎总治腰痛" - The Eight Liao points collectively treat lumbar pain. The text emphasizes that Ciliao BL-32 is the most clinically important of the four Liao points with the widest range of indications.
Jin Mei Hua Shi Chao:
"其主治功用举凡下焦前后阴、大小肠及腰腿诸症，无不包罗" - Its therapeutic functions encompass all disorders of the Lower Jiao, anterior and posterior genitalia, large and small intestines, as well as lumbar and leg conditions.
How to Locate
First identify the Tuffier's line which connects the highest points of the iliac crest. The spinous process of the 4th lumber vertebra (L4) mostly falls on this line. Then palpate in an inferior direction, passing L5, and reach the most superior 1st sacral foramen. Palpate further to reach the 2nd foramen, where Ciliao BL-32 is located. Here is to identify the 4 sacral foramens and the corresponding points at the same time. First locate the 4th sacral foramen on the level of the superior end of the rima ani (sometimes a bit more superiorly or inferiorly). Place the little finger on the 4th foramen, then the ring, middle and index fingers on a slightly V-shaped line in a superior direction, palpating for the depressions of the sacral foramens. With the fingers in this position, the index finger will be resting on Shangliao BL-31 of the 1st foramen, the middle finger on Ciliao BL-32 of the 2nd foramen, the ring finger on Zhongliao BL-33 of the 3rd foramen and the little finger on Xialiao BL-44 of the 4th foramen.
Caution
Reducing needling techniques are contraindicated during pregnancy except when specifically used to promote labor. This point is commonly used for labor induction and pain relief during childbirth, but should be avoided during earlier pregnancy stages due to its strong effect on the uterus and pelvic organs. Needling depth should be adjusted based on patient body weight and constitution - deeper insertion through the sacral foramen requires precise angle to avoid discomfort. The point is generally safe when needled correctly, but practitioners should ensure proper anatomical orientation to enter the sacral foramen effectively.
Needle Angle
45° (Oblique) / 90° (Perpendicular)
Depth Category
Deep
Standard Depth
1.0–2.0 cun
Needling Directions
Vertically 0.7–1 cun. Or 1.5-2 cun through the foramen. Caution:Reducing Needling techniques are contraindicated during pregnancy, except for promoting labor.
Expected Deqi Sensation
Deqi sensation typically manifests as local distension and soreness at the sacrum. With deeper needling (1.5–2 cun through the foramen), the sensation often radiates to the lower abdomen, perineum, or external genitalia. Some patients experience sensations spreading down the posterior thigh following the Bladder channel distribution. For gynecological conditions, a characteristic heaviness or fullness in the lower abdomen indicates optimal needle placement.
Moxibustion
Particularly Recommended
Duration: 15–30 minutes
Cupping
Recommended
Bloodletting
N/A
Gua Sha
Recommended
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