LOCATION
Level with the 2nd posterior sacral foramen, 1.5 cun lateral to the medial sacral crest.
Features
Back-Shu Point of the Urinary Bladder.
Body Inches (cun)
Each person has his/her own personal body inches.
One cun is equal to the width of the Knuckle of the thumb.
Nerves, vascular
Indication
Enteritis，constipation，diarrhea；lumbosacral neuralgia，sciatica；cystitis，enuresis；diabetes，dermatophytosis，uterus meningitis… Main point for all Bladder issues: from damp heat (painful a/or dark urination), from cold (frequent urination, incontinence). For dampness anywhere in the body, combine with SP 9 to expel dampness through urination.
Combinations
Pain in the lumbar spine，weakness of the lower limbs：BL 28 & GV 08 & ST 35.
Difficulty in urination：BL 28 & CV 03.
(Combining Shu-transport and Mu/alarm points)
Pruritus of vagina，stranguria with turbid discharge：BL 28 & LR 11 & SP 10.
Urinary tract infection：BL 23 & BL 28 & GB 34 & SP 06.
Prostatitis：BL 23 & BL 28 & CV 02 & SP 06. Cold and paralysis feet：BL 28 & BL 32 & KI 03.
穴位
在骶骨，第2骶後孔旁，後正中線旁開1.5寸。
特點
膀胱之背俞穴。
同身寸
針灸取穴比量法。出自《千金要方》。
是指以患者本人體表的某些部位折定分寸，
作为量取穴位的長度單位。
穴區神經血管
第一、二骶神經後支的外側支，骶外側動、靜脈後支，第五腰神經和第一、二、三骶神經後支的外側支分佈。
適應症
腸炎，便秘，痢疾；腰骶 神經痛，坐骨神經痛；膀胱炎，遺尿；糖尿病，腳氣，子宮內膜炎等。
穴位配伍療法
腰脊強痛，下肢無力：1.膀胱俞 2.筋縮 3.犢鼻
小便不利：1.膀胱俞 2.中極 (俞募配穴法)
陰部瘙癢，淋濁：1.膀胱俞 2.陰廉 3.血海
尿路感染：1.腎俞 2.膀胱俞 3.陽陵泉 4.三陰交
前列腺炎：1.腎俞 2.膀胱俞 3.曲骨 4.三陰交
足冷不仁：1.膀胱俞 2.次髎 3.太溪