BL23 Shenshu Acupuncture Point Guide

Practitioner Guide from The Acupuncture Supply Co.
Professional acupuncture supplies and practical clinical resources for qualified practitioners in Ireland and across Europe.

BL23, known as Shenshu (“Kidney Shu”), is the Back-Shu point of the Kidney channel. Located bilaterally in the lumbar region at the level of the second lumbar vertebra, it is traditionally selected in treatment strategies involving Kidney deficiency patterns, the lumbar region and knees, Jing, water metabolism, the ears and the Kidney’s role in grasping Qi.

BL23 is a familiar and important posterior point, but its position over deep lumbar and retroperitoneal structures makes accurate vertebral identification, proportional measurement and patient-specific anatomical assessment essential. This guide is a professional reference for appropriately trained practitioners, not a universal needling prescription or a self-treatment guide.

BL23 Shenshu quick reference

Point name	BL23 — Shenshu (“Kidney Shu”)
Channel	Bladder channel of Foot Taiyang
Classification	Back-Shu point of the Kidney
Region	Lumbar region
Laterality	Bilateral
Core landmark	Level with the inferior border of the spinous process of L2, 1.5 B-cun lateral to the posterior median line

Location of BL23 Shenshu

The World Health Organization standard locates BL23 in the lumbar region, at the same level as the inferior border of the spinous process of the second lumbar vertebra (L2), 1.5 B-cun lateral to the posterior median line.

How to locate BL23

1. Position the patient comfortably so the lumbar spine is supported, relaxed and fully accessible.
2. Identify the lumbar vertebral levels using more than one anatomical landmark rather than estimating from the waistline or umbilicus alone.
3. Confirm the inferior border of the L2 spinous process on the posterior median line.
4. Measure 1.5 B-cun laterally on each side, using the patient’s proportional measurement.
5. Palpate both points and assess symmetry, tissue depth, muscle tone, tenderness, skin condition and any altered anatomy before selecting a technique.

GV4 Mingmen lies on the posterior midline below the L2 spinous process and provides a useful level reference, while BL52 Zhishi lies farther laterally at the same level. BL23 should not be confused with BL22 at L1 or BL24 at L3. Vertebral counting should be confirmed carefully because body shape, pelvic position and palpable landmarks vary.

Traditional functions of BL23

Within traditional East Asian medicine, BL23 is commonly described as having the following functions:

• Tonifies the Kidney and supports Kidney Qi.
• Nourishes Kidney Yin and strengthens Kidney Yang according to the wider pattern and technique.
• Benefits Jing and Marrow within traditional theory.
• Strengthens the lumbar region and knees.
• Benefits the ears.
• Supports the Kidney’s role in regulating water passages.
• Supports the Kidney’s traditional function of grasping Lung Qi.
• Benefits reproductive and urinary function within an appropriate pattern strategy.

These are traditional descriptions used in acupuncture theory. They should not be interpreted as claims that BL23 has been proven to diagnose, prevent or cure kidney disease, infertility, respiratory illness, neurological disease or another medical condition.

Traditional clinical applications

BL23 may be considered within an individualised treatment plan when assessment and pattern differentiation indicate presentations involving:

• Chronic lumbar weakness, aching or coldness associated with a Kidney deficiency pattern.
• Weakness or soreness of the knees within a relevant traditional diagnosis.
• Fatigue, coldness, night sweating or other constitutional signs interpreted through Kidney Qi, Yin or Yang patterns.
• Urinary frequency, urgency, leakage or difficulty when the complete presentation supports its use.
• Reproductive or menstrual presentations involving Kidney deficiency.
• Tinnitus or hearing-related presentations within an appropriate traditional pattern.
• Breathlessness associated in traditional theory with the Kidney failing to grasp Qi, alongside appropriate medical care.
• Oedema or altered fluid metabolism within a complete treatment strategy.

Back pain, urinary change, breathlessness, hearing change and constitutional symptoms can indicate conditions requiring medical investigation. BL23 must not be used as a stand-alone response to new, severe, unexplained or progressive symptoms.

Common point combinations

Depending on the presentation and treatment principles, BL23 is traditionally combined with points such as:

• BL23 + KD3: commonly selected to support Kidney Qi, Yin or Yang according to the wider diagnosis.
• BL23 + GV4: traditionally considered in Kidney Yang deficiency, lumbar weakness and cold presentations.
• BL23 + CV4: used in strategies involving Kidney deficiency, Jing and the lower Jiao.
• BL23 + CV6: considered where supporting Kidney and original Qi forms part of the treatment principle.
• BL23 + BL40: a traditional local-distal combination for lumbar pain and Bladder-channel involvement.
• BL23 + SP6: considered in selected urinary, reproductive, Yin or fluid-metabolism patterns.

These combinations are traditional examples, not fixed prescriptions. Selection, laterality, stimulation, positioning and treatment frequency should be adapted to the patient, the complete diagnosis and the practitioner’s accredited training.

Anatomy and practitioner notes

• Superficial and muscular structures in the region may include skin, subcutaneous tissue, thoracolumbar fascia and the erector spinae or multifidus complex.
• The kidneys lie deep and anterior in the retroperitoneum; their level and lower pole position vary, and the right kidney is commonly lower than the left.
• Do not infer a safe depth from a standard illustration. Body habitus, muscle bulk, age, posture, spinal curvature and organ position differ between patients.
• Screen for renal or abdominal surgery, spinal surgery, scars, implanted hardware, structural deformity, osteoporosis, trauma, altered sensation, local swelling and significant anatomical variation.
• Inspect for infection, inflammation, bruising, pressure injury, skin lesions or other unsuitable tissue.
• Consider anticoagulant or antiplatelet medication, bleeding disorders, frailty, vasovagal history and needle sensitivity.
• Ensure prone positioning does not compromise breathing, circulation or comfort; adapt positioning for older, frail, pregnant or respiratory-compromised patients.
• Document assessment, consent, position, point selection, technique and response in accordance with applicable professional standards.

Needling and essential safety

BL23 requires sound lumbar anatomy and a controlled technique. Angle, depth and stimulation should be chosen according to accredited training, direct palpation and the patient’s individual tissue depth and medical history. This guide deliberately does not prescribe a universal angle or depth.

• Avoid deep, uncontrolled or forceful insertion: excessive depth can threaten the kidney or other retroperitoneal structures.
• Do not needle through infected, inflamed, wounded, bruised or otherwise unsuitable tissue.
• Use additional caution after lumbar, renal or abdominal surgery and where there are scars, implants, altered anatomy or reduced sensation.
• Use sterile, single-use acupuncture needles and appropriate hand hygiene, clean-field and sharps-disposal procedures.
• Stop and reassess if the patient experiences sharp or unexpected deep pain, marked radiating symptoms, breathlessness, faintness, unusual bleeding or another concerning response.

Moxibustion

Moxibustion is traditionally considered at BL23 in selected Cold or deficiency patterns when clinically appropriate and within the practitioner’s training. Protect the skin and maintain continuous supervision. Avoid moxa over impaired sensation, inflamed or damaged skin, in patients unable to report excessive heat, or when heat or smoke exposure is unsuitable.

When urgent medical assessment takes priority

Urgent assessment is required for severe or rapidly worsening back pain after significant trauma; new leg weakness; saddle numbness; new loss of bladder or bowel control; urinary retention; fever with spinal pain; collapse; or symptoms suggesting cauda equina syndrome, infection, fracture or another acute condition. Prompt medical evaluation is also important for visible blood in the urine, fever with flank pain, unexplained weight loss, night pain, a history of cancer with new back pain, or progressive neurological symptoms.

Research note

BL23 is included in acupuncture research involving low-back pain, urinary, reproductive and other presentations, usually as one point in a multi-point protocol. Inclusion in a protocol does not establish the independent effect of BL23, and results from one protocol or population should not be generalised. Traditional functions and clinical research should be described separately and without exaggerated claims.

Frequently asked questions

Where exactly is BL23 located?

BL23 is in the lumbar region, level with the inferior border of the L2 spinous process and 1.5 B-cun lateral to the posterior median line. It is bilateral.

What does Shenshu mean?

Shenshu is commonly translated as “Kidney Shu”. The name reflects BL23’s classification as the Back-Shu point traditionally associated with the Kidney.

Are BL23 and GV4 at the same spinal level?

Yes. GV4 is on the posterior midline below the L2 spinous process, while BL23 is located 1.5 B-cun laterally on both sides at the same level.

Why does BL23 require particular depth awareness?

The kidneys and other retroperitoneal structures lie deep and anterior to the posterior lumbar tissues. Their position and the thickness of the intervening tissues vary, so safe technique must be based on training and individual assessment rather than a fixed depth.

Can patients use this guide for self-needling?

No. BL23 is a posterior lumbar point requiring anatomical knowledge, safe positioning, sterile technique and professional assessment. This guide is intended only for qualified practitioners.

Continue exploring Project Lotus

Visit our Acupuncture Point Guides, read our KD3 / KI3 Taixi Guide, GB20 Fengchi Guide or ST36 Zusanli Guide.

Practitioners can also browse our collection of professional acupuncture needles, compare our ORCA silver-handle needles with guide tube, or explore our Complete Moxa Guide.

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Professional disclaimer: This article is provided for qualified acupuncture and healthcare practitioners for general educational purposes. Traditional actions and applications describe established acupuncture theory and are not claims of proven clinical efficacy. The content is not medical advice, does not replace accredited training and should not be used as a universal treatment protocol. Practitioners remain responsible for assessment, consent, safe technique, infection control, record keeping, referral and compliance with their professional and legal obligations.

Reference standards and safety reading:
World Health Organization. WHO Standard Acupuncture Point Locations in the Western Pacific Region.
World Health Organization. Guidelines on Basic Training and Safety in Acupuncture.
World Health Organization. WHO Benchmarks for the Practice of Acupuncture.
Huang CC, et al. Acupuncture: A Review of the Safety and Adverse Events and the Strategy of Potential Risk Prevention.
National Center for Complementary and Integrative Health. Acupuncture: Effectiveness and Safety.