窃闻肾之华在发。血之荣以发。盖发者血之余。血者水之类也。经言女子七岁发长。丈夫八岁发长。五八
发堕。八八发去者。盖肾主脑。脑者髓之海。发者脑之华。肾盛则发长。肾衰则发堕。脑减则发素也。其或年
少而发白。年老而发黑者。赋禀不同也。以部位分之。头上曰发。耳前曰鬓。中行属督脉。二行属太阳。三行
属少阳。头维额角。足阳明也。曲鬓悬颅。足少阳也。其经血气盛。则美而长。气多血少。则美而短。气少血多。
则少而恶。气血俱少。则其处不生。气血俱热。则黄而赤。气血俱衰。则白而落。察其经络之部位。可知其血
气之盛衰。其因病而变者。察之又有六法焉。曰逆上。曰冲起。曰直。曰落。曰润泽。曰枯槁。盖逆上者。死证也。
冲起者。绝候也。因疳积而发乱 者。可疗。因气竭而发直干枯者。不治。病久而发落者。精血虚。病风而
发落者。血液燥。润泽者。血气未竭。故生。枯槁者。血气已竭。故死。善诊者。察其发。观其证。可以知其逆从矣。
若夫发直如麻者。小肠绝。发结如穗者。小儿疳。面无血色。头发堕落者。血极之证。面色不变。头发逆上者。
痫病之征。汗出发润。喘不休者。肺先绝。齿长骨枯。发无泽者。骨先死。此皆诊发之目也。
头为五体之尊。百骸之长。自囟至心。如丝相贯不绝。是谓诸阳之会。精神之府。望之之法。可不深求其理
哉。按内经阳明之脉行于前。太阳之脉行于后。少阳之脉行于侧。厥阴之脉会于巅。督则自背中行而上
头至鼻。任则自腹中行而上颐循面。此皆经络之行。即部位之分也。由是以形言之。则骨部皆大者多寿。
骨部皆小者多夭。皮肉肿起者为实。皮肉陷下者为虚。囟陷者。脑髓不足而难治。囟肿者。脏腑不调而难
疗。骨缝不合者。赋禀弱。头项皆软者。血气亏。此察头形之纲领也。以容言之。则仰首者。其病在阳。俯首者。
其病在阴。蹙其额者。头痛。皱其眉者。心忧。头项强直者。邪气实。头垂倾欹者。正气虚。头独动摇者。风也。更
有心绝之证。头难回顾者。寒也。亦属阳明之经。此察头容之纲领也。夫如是。视上下以辨其经络。审左右
以究其逆从。合之五官。参之四诊。而形容之变。病症之殊。皆可识常通变矣。至于妊娠四月。欲知男女。遣
妊娠面南行。还复呼之。左回首者是男。右回首者是女。亦想当然耳。
I have heard that the luster of the kidneys manifests in the hair. The prosperity of blood is also reflected in the hair. Generally, hair is considered the surplus of blood, and blood belongs to the category of water. The classics state that girls' hair begins to grow at age seven, and boys' hair begins to grow at age eight. At forty (five times eight), hair begins to fall out; at sixty-four (eight times eight), hair falls out. This is because the kidneys govern the brain, which is the sea of marrow, and hair is the luster of the brain. When kidney qi is vigorous, hair grows; when kidney qi declines, hair falls out. When brain marrow decreases, hair turns white. Those who have white hair while young and black hair while old do so due to differences in innate constitution.
Dividing by location: hair on the head is called "fa," and hair before the ears is called "bin." The midline of the head belongs to the Du Meridian (Governing Vessel); the first line on either side belongs to the Taiyang Meridian (Greater Yang); the second line belongs to the Shaoyang Meridian (Lesser Yang). The Touwei acupoint and the temporal angle belong to the Foot-Yangming Stomach Meridian. The Qubin and Xuanlu acupoints belong to the Foot-Shaoyang Gallbladder Meridian. When the qi and blood of these meridians are vigorous, the hair is beautiful and long; when there is abundant qi but deficient blood, the hair is beautiful but short; when there is deficient qi but abundant blood, the hair is sparse and unattractive; when both qi and blood are deficient, hair does not grow in that area; when both qi and blood are hot, the hair turns yellow and red; when both qi and blood decline, the hair turns white and falls out. By observing the locations of the corresponding meridians, one can determine the prosperity or deficiency of qi and blood. Regarding changes caused by disease, there are six methods of observation: upward reversal, protruding upwards, straightness, falling out, moistness/luster, and withered/dryness. Generally, upward reversal indicates a death syndrome; protruding upwards indicates a terminal sign. Hair disorder due to infantile malnutrition (Gan accumulation) is treatable; hair becoming straight and dry due to exhaustion of qi is untreatable. Hair loss after prolonged illness indicates deficiency of essence and blood; hair loss due to wind disease indicates dryness of blood and fluids. Moist and lustrous hair indicates that qi and blood have not been exhausted, hence survival; withered and dry hair indicates that qi and blood have been exhausted, hence death. A skilled diagnostician, by observing the hair and correlating it with symptoms, can discern whether the disease course is favorable or unfavorable.
If the hair is straight like hemp, it indicates the exhaustion of the Small Intestine meridian; if the hair forms knots like tassels, it indicates pediatric Gan accumulation; if the face lacks color and hair falls out, it is a sign of extreme blood deficiency; if the facial complexion remains unchanged but the hair reverses upwards, it is a sign of epilepsy (Xian disease); if sweat makes the hair damp and panting continues without cessation, it indicates the prior exhaustion of the Lungs; if the teeth appear long, the bones are withered, and the hair lacks luster, it indicates the prior death of the bone essence. These are all key points in diagnosing via the hair.
The head is the most respected among the five body parts and the leader of the hundred bones. From the fontanelle to the heart, they are connected like threads without interruption; this is called the meeting point of all yang meridians and the residence of spirit and mind. How can the method of inspection fail to deeply explore its principles? According to the *Nei Jing* (Inner Canon), the Yangming meridian runs along the front, the Taiyang meridian runs along the back, the Shaoyang meridian runs along the sides, and the Jueyin meridian converges at the vertex. The Du meridian ascends from the midline of the back to the head and then to the nose; the Ren meridian ascends from the midline of the abdomen to the chin and follows the face. These are the pathways of the meridians, which correspond to the division of locations. From the perspective of form: those whose skeletal structures are generally large tend to live long lives; those whose skeletal structures are generally small tend to die young. Swollen skin and flesh indicate excess syndromes; sunken skin and flesh indicate deficiency syndromes. A sunken fontanelle indicates insufficient brain marrow and is difficult to treat; a swollen fontanelle indicates disharmony of the zang-fu organs and is difficult to cure. Unfused cranial sutures indicate weak constitution; a soft head and neck indicate deficiency of qi and blood. These are the general principles for inspecting the shape of the head. From the perspective of demeanor: looking upwards indicates a disease in the Yang; looking downwards indicates a disease in the Yin; furrowing the forehead indicates headache; knitting the eyebrows indicates mental worry; stiffness and rigidity of the head and neck indicate excess pathogenic factors; drooping or tilting of the head indicates deficiency of healthy qi; isolated trembling of the head indicates wind pathology. Additionally, in cases of Heart exhaustion where the head is difficult to turn back, this indicates cold pathology, which also pertains to the Yangming meridian. These are the general principles for inspecting the demeanor of the head. Thus, by observing up and down to distinguish meridians, and examining left and right to investigate favorability or unfavorability, combined with the inspection of the five sense organs and reference to the four diagnostic methods, variations in appearance and differences in diseases can be understood through standard patterns and adaptive changes. As for determining the gender of a fetus at four months of pregnancy, one may have the pregnant woman walk facing south and then call her name; if she turns her head to the left, it is a boy; if she turns her head to the right, it is a girl. However, this is merely speculative reasoning.