九针之宜，各有所为，长短大小，各有所施。刺热者用 针，刺寒者用毫针，刺大者用
锋针
，刺小者用员利针，刺痈者用铍针。 针出泻阳气；员针者揩摩分肉间，不得伤肌肉，以泻
分气； 针者主按脉勿陷，以致其气，令邪气勿陷；锋针者以发痼疾；铍针者以取大脓；员
利针者以取暴气；毫针者静以徐往，微以久留，而痒以取痛痹；长针者可以取远痹；大针者
以泻机关之水。病在皮肤，取以 针，于病所肤白勿取。病在分肉间，取以员利针，于病所
，病在脉气，少当补之者，取之 针于井荥分输。病为大脓者，取以铍针。病痹气暴发者，
取以员利针。病痹气痛而不去者，取以毫针。病在中者，取以长针。水肿不能过关节者，取
以大针。以小治小者其功小，以大治大者多害，故其以成脓血者，其惟砭石铍针之所取也。
凡刺有五，以应五脏。一曰半刺，半刺者浅内而疾发针，无针伤肉，如拔毛状，以取皮
气，
此肺之应也。二曰豹文刺，豹文刺者，左右前后针之，中脉为故，以取经络之血者，此心之
应也。三曰关刺，关刺者直刺左右尽筋上，以取筋痹，慎无出血，此肝之应也，或曰渊刺，
一曰岂刺。四曰合谷刺，合谷刺者，左右鸡足，针于分肉之间，以取肌痹，此脾之应也。五
曰输刺，输刺者，直入直出，深内之至骨，以取骨痹，此肾之应也。
九针的适宜应用，各有其特定的作用，长短大小，各自有不同的施用范围。针刺热证用镵针（chán zhēn，一种针尖锋利的针），针刺寒证用毫针（háo zhēn，细长的针），刺实证用锋针（fēng zhēn，三棱针），刺虚证用员利针（yuán lì zhēn，针身较粗且尖锐的针），刺痈疽用铍针（pí zhēn，形如宝剑的针）。镵针用于泻除阳气；员针在肌肉间隙进行揩摩，不损伤肌肉，以泻除分肉间的邪气；圆针（yuán zhēn，针头椭圆如黍米的针）主要用于按压经脉而不陷入，以引导正气，防止邪气内陷；锋针用于治疗顽固性疾病；铍针用于切开排脓；员利针用于祛除暴发的邪气；毫针通过静候气至、缓慢进针、轻微留针，来治疗瘙痒和痛痹；长针（zhǎng zhēn，针身较长的针）可以治疗深部的痹症；大针（dà zhēn，针身粗大的针）用于泻除关节腔内的积水。病位在皮肤的，用镵针，若病变部位肤色苍白则不宜使用。病位在分肉间的，用员利针，若病变部位肤色发黑则不宜使用。病位在脉气方面，需要少补的，取井穴、荥穴、输穴，用圆针操作。病为大量积脓的，用铍针。病为痹气暴发的，用员利针。病为痹气疼痛而久治不愈的，用毫针。病位在中焦或深层的，用长针。水肿不能越过关节的，用大针。用小针治疗大病效果微小，用大针治疗小病多有危害，所以对于已成脓血的病症，只有砭石和铍针才能处理。
凡是有五种刺法，分别对应五脏。第一种叫半刺，半刺是浅刺并迅速出针，不伤及肌肉，状如拔毛，用以取皮部之气，这是与肺相应的刺法。第二种叫豹文刺，豹文刺是在病变部位的左右前后多针刺入，以刺中血脉为原则，用以祛除经络中的瘀血，这是与心相应的刺法。第三种叫关刺，关刺是直接刺入关节两侧的肌腱尽头处，用以治疗筋痹，务必注意不要出血，这是与肝相应的刺法，有的称为渊刺，也有的称为岂刺。第四种叫合谷刺，合谷刺是将针向左右斜刺，呈鸡足状，刺入分肉之间，用以治疗肌痹，这是与脾相应的刺法。第五种叫输刺，输刺是直入直出，深刺至骨部，用以治疗骨痹，这是与肾相应的刺法。
The appropriate applications of the Nine Needles each have specific functions, and their lengths and sizes are applied differently. For heat syndromes, use the Chan Needle (Chanzhen, a needle with a sharp tip); for cold syndromes, use the Hao Needle (Haozhen, a fine and long needle); for excess syndromes, use the Feng Needle (Fengzhen, a triangular-edged needle); for deficiency syndromes, use the Yuanli Needle (Yuanlizhen, a needle that is thicker and sharper); for carbuncles, use the Pi Needle (Pizhen, a needle shaped like a sword). The Chan Needle is used to drain Yang Qi; the Yuan Needle is used for rubbing between muscle compartments without damaging the muscles, thereby draining the pathogenic Qi from the intermuscular spaces; the Yuan Round Needle (Yuanyuanzhen, a needle with an oval head) is mainly used for pressing on meridians without sinking in, to guide Zheng Qi and prevent pathogenic factors from sinking deeper; the Feng Needle is used to treat chronic diseases; the Pi Needle is used to drain large amounts of pus; the Yuanli Needle is used to dispel sudden onset of pathogenic Qi; the Hao Needle treats itching and painful Bi syndrome by waiting quietly for Qi arrival, inserting slowly, and retaining lightly for a long time; the Chang Needle (Changzhen, a longer needle) can treat deep-seated Bi syndrome; the Da Needle (Dazhen, a thick needle) is used to drain water accumulation in joints. When the disease is in the skin, use the Chan Needle; do not use it if the skin at the lesion site is pale. When the disease is in the intermuscular spaces, use the Yuanli Needle; do not use it if the skin at the lesion site is dark. When the disease involves Qi and Blood in the vessels, requiring slight tonification, use the Yuan Round Needle at the Jing-Well, Ying-Spring, and Shu-Stream points. For diseases involving large accumulations of pus, use the Pi Needle. For diseases involving sudden onset of Bi Qi, use the Yuanli Needle. For diseases involving persistent pain from Bi Qi, use the Hao Needle. For diseases located in the interior or deep layers, use the Chang Needle. For edema that cannot cross the joints, use the Da Needle. Using small needles to treat large diseases yields little effect, while using large needles to treat small diseases causes much harm. Therefore, for conditions where pus and blood have already formed, only Bian Shi (stone knives) and the Pi Needle are suitable.
There are five types of needling methods, corresponding to the Five Zang Organs. The first is called Ban Ci (Half Puncture). Ban Ci involves shallow insertion and rapid withdrawal without damaging the muscles, resembling the pulling of hair, to extract Qi from the skin layer; this corresponds to the Lung. The second is called Bao Wen Ci (Leopard Pattern Puncture). Bao Wen Ci involves multiple insertions around the left, right, front, and back of the lesion, aiming at the vessels, to remove stagnant blood from the collaterals; this corresponds to the Heart. The third is called Guan Ci (Joint Puncture). Guan Ci involves direct insertion into the tendons at the ends of the joint on both sides to treat tendon Bi, taking care not to cause bleeding; this corresponds to the Liver. It is also known as Yuan Ci or Qi Ci. The fourth is called He Gu Ci (Valley Convergence Puncture). He Gu Ci involves oblique insertion to the left and right, forming a chicken-foot shape, inserted between muscle compartments to treat muscle Bi; this corresponds to the Spleen. The fifth is called Shu Ci (Transport Puncture). Shu Ci involves direct insertion and withdrawal, penetrating deeply to the bone, to treat bone Bi; this corresponds to the Kidney.