美眉者太阳多血，通髯极须者少阳多血，美须者阳明多血。然则妇人无须者，无血气乎。曰∶冲脉、任
脉，皆起于胞中，上循背里，为经络之海。其浮而外者，循腹右上行，会于咽喉，别而络唇口。血气盛则充肤
热肉，血独盛则澹渗皮肤，生毫毛。妇人之生也，有余于气，不足于血，以其数脱血也，冲任之脉，不荣唇
口，故须不生矣。士人有伤于阴，阴气绝而不起，（阴气即阴器，非误。）阴不用，然其须不去，
而宦者独去，何也？曰∶宦者其宗筋伤，其冲脉血泻不复，皮肤内结，唇口不荣，故须不生矣。其有天宦者，
未尝被伤，不脱于血，然其须不生何也？曰∶此天之所不足也，其任冲不盛，宗筋不成，有气无
血，唇口不荣，故须不生矣。（上妇宦无须。）
阳明多血多气，太阳多血少气，少阳多气少血，太阴多
血少气，（一作少血多气。林亿引杨上善《太素》云∶太阴与阳明表里，血气
俱盛，当是多血多气。）厥阴多血少气，（一作多气少血。）少阴多气少血。
（一作多血少气。）是故刺阳明出血气，刺太阳出血恶气，（恶，去声。不欲出气也。）刺少阳出气恶血，刺
太阴出血恶气，刺厥阴出血恶气，刺少阴出气恶血也。（上六经气血多少。并出《灵枢》。）
（出《灵枢》）
春青风，夏阳风，秋凉风，冬寒风。凡此四时之风，其所病各不同形。黄色薄皮弱肉者，不胜春之
虚风。白色薄皮弱肉者，不胜夏之虚风。青色薄皮弱肉者，不胜秋之虚风。赤色薄皮弱肉者，不胜冬之虚风
也。黑色而皮浓肉坚，固不伤于四时之风。其皮薄而肉不坚色不一者，（色不正黑。）长夏至
而有虚风即病矣。其皮浓而肌肉坚者，长夏至而有虚风不病也，必重感于寒，外内皆然乃病。故材木之异也，
皮之浓薄，汁之多少，而各不同。木之早花先叶者，遇春霜烈风，则花落而叶萎。久曝大旱，则脆木薄皮者，
枝条汁少而叶萎。久阴淫雨，则薄皮多汁者，皮溃而漉。卒风暴起，则刚脆之木
枝折杌伤。秋霜疾风，则刚脆之木根摇而叶落。凡此五者，各有所伤，况于人乎。（杌同 。）
眉毛秀美的人，是太阳经气血旺盛、血液充盈的表现；胡须通达且极为浓密的，是少阳经气血旺盛、血液充盈的表现；胡须美观的，是阳明经气血旺盛、血液充盈的表现。既然这样，那么妇女没有胡须，难道是没有血气吗？回答说：冲脉和任脉，都起始于胞宫（子宫），向上沿着脊柱内部行走，成为经络之海。其中浮行于体表的分支，沿着腹部右侧上行，汇聚于咽喉部，分出支脉联络口唇。当血气旺盛时，就能充养皮肤、温暖肌肉；如果血液特别旺盛，就能渗透皮肤，生长毫毛。妇女的生理特点，是气有余而血不足，这是因为她们经常因月经等原因耗损血液，导致冲脉和任脉的气血不能荣润口唇，所以胡须不生。
士人如果阴器受到损伤，导致阴气断绝而不能勃起（注：这里的“阴气”指阴器，并非误写），阴器功能丧失，但是胡须并不脱落；然而宦官（阉人）的胡须却脱落了，这是为什么呢？回答说：宦官是因为宗筋（生殖器及其周围组织）受损，冲脉的血气泻出后无法恢复，皮肤内部结滞，口唇得不到荣润，所以胡须不生。那些天生宦者（天宦，指先天发育不良无胡须者），未曾遭受外伤，也没有失血，但是为什么也不生胡须呢？回答说：这是先天禀赋不足，他们的任脉和冲脉不旺盛，宗筋发育不全，只有气而没有血，口唇得不到荣润，所以胡须不生。（以上论述妇女、宦官、天宦无须的情况。）
阳明经多血多气，太阳经多血少气，少阳经多气少血，太阴经多血少气（另一种说法认为是少血多气。林亿引用杨上善《太素》的观点说：太阴与阳明互为表里，血气都旺盛，应当是多血多气），厥阴经多血少气（另一种说法认为是多气少血），少阴经多气少血（另一种说法认为是多血少气）。因此，针刺阳明经可以放出血和气，针刺太阳经可以放出血而不宜放出气（恶，读去声，意为厌恶、不宜），针刺少阳经可以放出气而不宜放出血，针刺太阴经可以放出血而不宜放出气，针刺厥阴经可以放出血而不宜放出气，针刺少阴经可以放出气而不宜放出血。（以上论述六经气血多少的规律，均出自《灵枢》。）
（出自《灵枢》）
春天的风叫青风，夏天的风叫阳风，秋天的风叫凉风，冬天的风叫寒风。这四季的风邪，所导致的疾病形态各不相同。面色黄、皮肤薄、肌肉软弱的人，承受不住春季的虚风侵袭。面色白、皮肤薄、肌肉软弱的人，承受不住夏季的虚风侵袭。面色青、皮肤薄、肌肉软弱的人，承受不住秋季的虚风侵袭。面色赤、皮肤薄、肌肉软弱的人，承受不住冬季的虚风侵袭。面色黑、皮肤厚、肌肉坚实的人，本来就不受四季风邪的伤害。如果皮肤薄、肌肉不坚实且面色不正（如非黑色），那么在长夏时节遇到虚风就会发病。如果皮肤厚、肌肉坚实，在长夏时节遇到虚风也不会发病，除非再次感受寒邪，内外皆受邪才会生病。这就好比木材的差异一样，有的皮厚皮薄，有的汁液多汁液少，各不相同。树木如果早开花先长叶，遇到春霜烈风，花朵就会凋落、叶子枯萎。长期暴晒大旱，脆性木、薄皮木枝条汁液少而叶子枯萎。长期阴雨连绵，薄皮多汁的树木，树皮溃烂流液。突然刮起暴风，刚硬脆性的树木树枝折断受伤。秋霜疾风，刚硬脆性的树木根部摇动、叶子掉落。这五种情况，各自有所伤害，何况是人呢？（“杌”同“兀”，指树木砍去枝干后的树桩，此处引申为受伤折断。）
Individuals with beautiful eyebrows indicate that the Taiyang channel (Taiyang Meridian) is abundant in blood. Those with whiskers extending fully and extremely thick beards indicate that the Shaoyang channel (Shaoyang Meridian) is abundant in blood. Those with aesthetically pleasing beards indicate that the Yangming channel (Yangming Meridian) is abundant in blood. Given this, do women without beards lack blood and qi? The answer is: The Chong vessel (Penetrating Vessel) and Ren vessel (Conception Vessel) both originate from the Baozhong (uterus/womb), ascend along the interior of the back, and serve as the sea of the meridians. Their branches floating outward follow the right side of the abdomen upward, converge at the throat, and branch off to connect with the lips and mouth. When blood and qi are abundant, they nourish the skin and warm the flesh; when blood is particularly abundant, it permeates the skin and generates body hair. Women are physiologically characterized by an excess of qi and a deficiency of blood, primarily because they frequently lose blood through menstruation. Consequently, the Chong and Ren vessels fail to nourish the lips and mouth, resulting in the absence of beard growth.
If a scholar suffers injury to the yin organ (genitals), causing the yin qi to cease and function to fail (note: "yin qi" here refers to the genitalia, not a textual error), and the genitals become impotent, yet the beard does not fall out; however, eunuchs' beards do fall out. Why is this? The answer is: Eunuchs suffer damage to the Zongjin (tendons of the genitals/genital region), causing the blood of the Chong vessel to drain and fail to recover. Internal stagnation occurs in the skin, the lips and mouth are not nourished, and thus the beard does not grow. What about those born as "Tianhuan" (heavenly eunuchs/congenitally hairless)? They have never suffered trauma nor lost blood, yet why do they not grow beards? The answer is: This is due to congenital insufficiency. Their Ren and Chong vessels are not vigorous, the Zongjin fails to develop properly, there is qi but no sufficient blood, the lips and mouth are not nourished, and thus the beard does not grow. (The above discusses the conditions for women, eunuchs, and Tianhuan lacking beards.)
The Yangming channel is abundant in both blood and qi. The Taiyang channel is abundant in blood but deficient in qi. The Shaoyang channel is abundant in qi but deficient in blood. The Taiyin channel is abundant in blood but deficient in qi (another version states deficient in blood and abundant in qi. Lin Yi cites Yang Shangshan's *Taisu*, stating: Since Taiyin and Yangming are exterior-interior pairs with both blood and qi abundant, it should be abundant in both blood and qi). The Jueyin channel is abundant in blood but deficient in qi (another version states abundant in qi and deficient in blood). The Shaoyin channel is abundant in qi but deficient in blood (another version states abundant in blood and deficient in qi). Therefore, needling the Yangming channel can release both blood and qi; needling the Taiyang channel can release blood but should avoid releasing qi (the character 'e' is pronounced with the departing tone, meaning 'to dislike' or 'avoid'); needling the Shaoyang channel can release qi but should avoid releasing blood; needling the Taiyin channel can release blood but should avoid releasing qi; needling the Jueyin channel can release blood but should avoid releasing qi; needling the Shaoyin channel can release qi but should avoid releasing blood. (The above outlines the abundance and deficiency of blood and qi in the six channels, all sourced from the *Ling Shu*.)
(From the *Ling Shu*)
Spring wind is called Qingfeng (Green Wind); summer wind is called Yangfeng (Sun Wind); autumn wind is called Liangfeng (Cool Wind); winter wind is called Hanfeng (Cold Wind). The diseases caused by these seasonal winds manifest differently. Individuals with yellow complexion, thin skin, and weak flesh cannot withstand the empty wind of spring. Those with white complexion, thin skin, and weak flesh cannot withstand the empty wind of summer. Those with blue/green complexion, thin skin, and weak flesh cannot withstand the empty wind of autumn. Those with red complexion, thin skin, and weak flesh cannot withstand the empty wind of winter. Individuals with black complexion, thick skin, and firm muscle are naturally resistant to the winds of the four seasons. However, those with thin skin, unfirm muscle, and irregular complexion (not truly black) will fall ill if exposed to empty wind during the late summer period. Those with thick skin and firm muscle will not fall ill even if exposed to empty wind during late summer, unless they are doubly affected by cold, suffering from both external and internal pathogenic factors. This is analogous to the differences among timber: some have thick bark, some thin; some have much sap, some little. Trees that flower early and leaf before others, when encountering spring frost and fierce winds, will have their flowers fall and leaves wither. Under prolonged exposure and severe drought, brittle trees with thin bark will have few juices in their branches and withered leaves. Under prolonged heavy rain, trees with thin bark and high sap content will have rotting bark and leaking fluids. Sudden violent storms will cause rigid and brittle trees to break their branches and suffer structural damage. Autumn frost and rapid winds will cause rigid and brittle trees to shake their roots and drop their leaves. All these five scenarios involve specific types of damage; how much more so for humans? ('Wu' is identical to 'Wu', referring to a tree stump, here implying broken or damaged wood.)