Acupuncture Point Weishu (BL21)
Location:
Lie prostrate or pronely; at the level of the lower border of spinous process of the 12th thoracic vertebra, 1.5 cun apart from the posterior median line laterally.

Function:
Invigorating the spleen and stomach, and removing stagnation.

Regional Anatomy:
Skin-subcutaneous tissue-superficial layer of thoracolumbar fascia and aponeurosis of latissimus muscle of back-erector spinal muscle.
In the superficial layer, there are the cutaneous branches of the posterior branches of the 12th thoracic and 1st lumbar nerves and the accompanying arteries and veins. In the deep layer, there are the muscular branches of the posterior branches of the 12th thoracic and 1st lumbar nerves and the branches or tributaries of the related arteries and veins.

Indications:
Gastrohelcoma, gastritis, carcinoma of stomach, grastric dilatation, gastroptosis, gastrospasm, hepatitis, pancreatitis, enteritis, dysentery, icterus, hydrops, Asthma, infantile night blindness, Diabetes, anorexia, sleeplessness, backache.

Prescription:
Combined use with ZusanliST36 (Zusanli (ST 36) He-Sea Point) for treatmen of grastritis and dyspepsia; with YinlingquanSP9 (Yinlingquan (SP9) He-Sea Point) for treatmen of dysentery; with GuanyuanCV4(Guanyuan (CV4) Front-Mu Point of the SmallIntestine) for treatmen of irregular menstruation; with ShenshuBL23 (Shenshu (BL23)), ShimenCV5 (Shemen (CV5) Front-Mu Point of Sanjiao), ZhongtingCV16 (Zhongting (CV16)) for treatmen of vomiting; and with ZusanliST36 (ST36), ZhongwanCV12 (Acupuncture Single Point Zhongwan (CV12) Front-Mu Point of the Stomach) for treatmen of anorexia.

Methods:
Insert the needle obliquely 0.5-0.8 cun deep; needling response: local numbness and distension; moxibustion: using 3-5 moxa-cones, or mild moxibustion for 15 min.
Note:
Don`t puncture deeply and obliquely toward the upper aspect, or else the needle would penetrate the transversospinal muscle-the diaphragmatic pleura-the costodiaphragmatic recess-the visceral pleura and the lung tissue, and cause an injury to lung tissue, leading to pneumatothorax.