夫小儿三岁以下有病。须看男左女右手虎口三关纹理。两手食指本节为风关。中节为气
关。
第三节为命关。其纹曲直不同。如纹只在本节。病易治。通过中节则病重。过第三节则难治
惊则纹青。淡红则寒热在表。深红必主伤风痘疹。
纹乱则病久。纹细则腹痛多啼。乳食不消。纹粗直射指甲。必主惊风恶候。纹黑如墨。
必困重难医。此乃神圣工巧之一端也。
\r虎口三关脉纹图\pt164a2.bmp\r
虎口。叉手处是也。三关在第二指。应看三节。
第一节风关。第二节名气关。第三节名命关。
小儿食指辨三关。男左女右一般看。皆知初气中风候。末是命门易亦难。要知虎口气纹
脉。
倒指看纹分五色。红黄安乐五脏和。红紫依稀有损益。紫青伤食气虚烦。青黑之时症候逆。
忽然纯黑在其间。好手医人心胆寒。若也直上到命关。粒米短长分两端。如枪冲射惊风至。
分作枝叉有数般。弓反里顺外为逆。顺逆交连顺已难。叉头长短犹可救。如此医人仔细看。
初
看掌心中有热。便知身体热相从。肚热脚冷伤积定。脚热额热是感风。额冷脚热惊所得。疮
疹发来耳后红。孩子无事忽大叫。不是惊风是天吊。大叫气促长声粗。误吃热毒闷心窍。急
须吐下却和脾。若将惊药真堪笑。痢后努气眉头皱。不努不皱肠有风。冷热不调分赤白。脱
肛因毒热相攻。十二种痢何为恶。噤口刮肠大不同。孩儿有病不可下。不热自汗兼自泻。神
困囟陷四肢冷。干呕气虚神怯怕。吐虫面白毛憔悴。府气潮热食不化。鼻塞咳嗽及虚痰
脉细肠鸣烦躁讶。方将有积与疏通。下了之时必生诧。孩儿实热下无辜。面赤睛红气壮强
脉大弦洪肚上热。胙腮喉痛尿如汤。屎硬腹胀胁肋满。四肢浮肿夜啼长。遍体生疮肚隐痛
下之必愈是为良。
凡是三岁以下的小儿患病，必须观察男孩左手、女孩右手的虎口三关指纹。两手食指的近端指节称为风关，中间指节称为气关，远端指节称为命关。指纹的形态曲直各不相同。如果指纹只显露在近端指节（风关），病情容易治疗；如果透过中间指节（气关），则病情较重；如果到达远端指节（命关），则难以治疗。
受惊时，指纹呈青色；淡红色表示寒热之邪在体表；深红色必定主伤风或痘疹病证。
指纹杂乱表示病程长久；指纹纤细表示腹痛且多啼哭，乳食不消化；指纹粗直并射向指甲，必定主惊风等危重证候；指纹黑如墨色，必定是困顿沉重、难以医治。这是中医“神、圣、工、巧”四诊技巧中的一方面。
虎口，即手指交叉处的部位。三关位于第二指（食指）上，应当观察三个指节。
第一节为风关，第二节为气关，第三节为命关。
小儿食指的指纹可以辨别三关的情况，男孩看左手、女孩看右手，方法是一样的。都知道初起阶段对应风关，反映中风候；末端对应命关，病情既容易判断也较难治。要了解虎口的气纹脉象，需要倒转手指观察，分辨五色。红黄色代表五脏调和，安乐健康；红紫色隐约可见损伤或不足；紫青色代表伤食、气虚烦闷；青黑色出现时，病症逆乱；忽然间纯黑色出现在其中，即使是高明的医生也会感到心惊胆战。如果指纹直上达到命关，以米粒长短来区分两端情况。像枪一样冲射而来，是惊风至；分作枝叉状有多种情形。弓形反背向内为顺，向外为逆。顺逆交错相连，顺证已属难治。叉头长短尚可救治。如此细致的诊断，医生必须仔细观察。
初看手掌心是否有热，便知身体是否发热。肚子热而脚冷，确定是积滞伤食；脚热额头热，是感受风邪；额头冷脚热，是受惊所得；疮疹发作时耳后发红。孩子没有生病却突然大叫，不是惊风就是天吊病。大叫、气促、声音长而粗，可能是误吃热毒之物导致心窍闭塞。急需使用吐下法调和脾胃，如果使用镇惊药物真是可笑。痢疾之后努责但眉头紧皱，不努责也不皱眉则是肠中有风。冷热不调分为赤痢和白痢；脱肛是因为毒热相互攻冲。十二种痢疾中哪些是恶性的？噤口痢和刮肠痢大不相同。
孩子有病不可轻易使用泻下法。如果不发热、自汗、自泻，精神困倦、囟门凹陷、四肢冰冷，干呕、气虚、神怯害怕，呕吐虫体、面色苍白、毛发憔悴，府气潮热、食物不消化，鼻塞咳嗽及虚痰，脉细、肠鸣、烦躁惊讶。此时方有积滞才考虑疏通，如果此时泻下，必定产生变证。如果孩子是实热证，可以使用泻下法。表现为面赤、眼红、气息壮盛强劲、脉象大弦洪、肚子上热、腮肿喉痛、小便如汤、大便硬结、腹胀、胁肋满闷、四肢浮肿、夜间长时间啼哭、遍体生疮、腹部隐痛。此时泻下必定痊愈，这才是良法。
When children under three years of age are ill, one must examine the fingerprint patterns on the Tiger's Mouth (Hu Kou) Three Passes (San Guan) of the left hand for boys and the right hand for girls. The proximal phalanx joint of the index finger is called the Wind Pass (Feng Guan); the middle phalanx joint is called the Qi Pass (Qi Guan); and the distal phalanx joint is called the Life Pass (Ming Guan). The patterns vary in curvature and straightness. If the pattern appears only at the proximal joint (Wind Pass), the disease is easy to treat; if it extends through the middle joint (Qi Pass), the disease is severe; if it reaches the distal joint (Life Pass), it is difficult to treat.
A blue-green pattern indicates fright (Jing); a pale red color indicates cold-heat pathogens at the exterior (Biao); a deep red color necessarily indicates wind injury or smallpox/rubella conditions.
A chaotic pattern indicates a long-standing disease; a fine/thin pattern indicates abdominal pain with frequent crying and indigestion of milk and food; a thick, straight pattern extending toward the nail tip necessarily indicates convulsions (Jing Feng) and critical conditions; a black pattern like ink indicates a critical, difficult-to-treat condition. This constitutes one aspect of the "Divine, Sage, Artisan, and Skillful" diagnostic techniques.
The Tiger's Mouth refers to the area where the thumb and index finger cross. The Three Passes are located on the second finger (index finger), corresponding to the three joints.
The first joint is the Wind Pass; the second joint is the Qi Pass; the third joint is the Life Pass.
The fingerprint on the child's index finger distinguishes the Three Passes. For boys, observe the left hand; for girls, the right hand—the method is the same. It is known that the initial stage corresponds to the Wind Pass, reflecting wind-strike patterns; the terminal end corresponds to the Ming Gate (Life Pass), which is both easy to perceive and difficult to cure. To understand the Qi patterns and pulses of the Tiger's Mouth, invert the finger to observe and distinguish five colors. Red and yellow indicate harmonious internal organs and peace; red-purple suggests slight damage or deficiency; purple-blue indicates food retention, Qi deficiency, and irritability; when green-black appears, the symptoms are adverse/rebellious; if pure black suddenly appears among them, even skilled physicians may feel their courage falter. If the pattern rises straight to the Life Pass, its length relative to a grain of rice divides the prognosis into two ends. A pattern shooting forth like a spear indicates the arrival of convulsions; branching into twigs presents several variations. An arch curving inward is favorable (Shun); outward is unfavorable (Ni). When favorable and unfavorable intertwine, even the favorable becomes difficult. Variations in branch length can still be saved. Physicians must examine such details carefully.
Initially, check if the palm is hot to know if the body is feverish. Heat in the abdomen with cold feet confirms food stagnation; heat in the feet and forehead indicates wind invasion; cold forehead with hot feet indicates fright; redness behind the ears signals the eruption of sores/rashes. If a healthy child suddenly cries out loudly, it is either convulsions or Tian Diao disease. Loud crying, rapid breathing, and long, coarse sounds suggest ingestion of hot toxins blocking the heart orifices. Urgent emetic or purgative methods are needed to harmonize the Spleen and Stomach; using anti-convulsant drugs would be laughable. After dysentery, straining with furrowed brows indicates intestinal wind; no straining and no furrowing also indicates intestinal wind. Cold-heat imbalance differentiates red and white dysentery; rectal prolapse is caused by toxic heat attacking internally. Among the twelve types of dysentery, which are malignant? Jin Kou Li (closed-mouth dysentery) and Gua Chang Li (scraping-intestine dysentery) are vastly different.
Children should not be treated with purgatives indiscriminately. If there is no fever but spontaneous sweating and diarrhea, with mental fatigue, sunken fontanelle, and cold limbs; dry heaving, Qi deficiency, timidity, vomiting worms, pale complexion, and brittle hair; Fu Qi tidal fever, indigestion, nasal congestion, cough, deficient phlegm, fine pulse, borborygmus, and irritability—then there is accumulation, and only then should one consider unblocking. Purgation at this stage will surely cause complications. However, if the child has excess-heat, purgation is permissible. Signs include red face, red eyes, strong breath, large/stringy/hurrying pulse, abdominal heat, mumps/sore throat, urine like boiling water, hard stool, abdominal distension, fullness in hypochondrium, edema of four limbs, prolonged night crying, widespread sores, and dull abdominal pain. In such cases, purgation leads to recovery and is the excellent method.