《难经》曰∶损脉之为病奈何？然∶一损损于皮毛，皮聚而毛落。二损损于血脉，血脉
虚少，不能荣于五脏六腑。三损损于肌肉，肌肉消瘦，饮食不能为肌肤。四损损于筋，筋缓
不能自收持。五损损于骨，骨痿不能起于床。反此者，至脉之病也。从上下者，骨痿不能起
于床者死；从下上者，皮聚而毛落者死。治损之法∶损其肺者，益其气。损其心者，调
其营卫。损其脾者，调其饮食，适其寒温。损其肝者，缓其中。损其肾者，益其精，此治损
之法也。不能治其虚，安问其余？故曰∶实实虚虚，损不足而益有余，此中工之所害也。
（宾）按此上损下损之说，其义极精，然有未尽者，犹宜悉也。盖凡思虑劳倦外感等证
则伤阳，伤于阳者，病必自上而下也；色欲醉饱内伤等证则伤阴，伤于阴者，病必自下而上
也。如经曰∶二阳之病发心脾，有不得隐曲，女子不月之类，此即自上而下者也。又经曰∶
五脏主藏精者也，不可伤，伤则失守而阴虚，阴虚则无气，无气则死矣，此即自下而上者也
。盖自上而下者，先伤乎气。故一损损于肺，则病在声息肤腠。二损损于心，则病在血脉颜
色。三损损于胃，则病在饮食不调。四损损于肝，则病为螈 疼痛。五损损于肾，则病为骨
痿、二便不禁。此先伤于阳，而后及乎阴，阳竭于下，则孤阴无以独存，不可为也。自下而
上者，先伤乎精。故一损损于肾，则病为泉源干涸。二损损于肝，则病为血动筋枯。三损损
于脾，则病为痰涎壅盛。四损损于心，则病为神魂失守。五损损于肺，则病为喘急短气。此
先伤乎阴，而后及乎阳，阴竭于上，则孤阳无以独生，不可为也。故曰∶心肺损而神衰，肝
肾虚而形敝，脾胃损而食饮不归血气。凡明哲之士，则当察所由，而预防其渐，又何虚损之
可虑？若待源流俱竭，而后归罪于药之不效，医之不良，此其愚也亦甚矣。
《巢氏病源》曰∶夫虚劳者，五劳七伤六极是也。一曰志劳，二曰思劳，三曰心劳，四
曰忧劳，五曰瘦劳。又有肺劳者，短气而面浮，鼻不闻香臭。肝劳者，面目干黑，口苦，精
神不守，恐畏不能独卧，目视不明。心劳者，忽忽喜忘，大便苦难，或时鸭溏，口内生疮。
脾劳者，舌本苦直，不得咽唾。肾劳者，背难以俯仰，小便不利，色赤黄而有余沥，茎内痛
，阴囊湿生疮，小腹满急。六极者，一曰气极，令人内虚，五脏不足，邪气多，正气少，不
欲言。二曰血极，令人无颜色，眉发落，忽忽喜忘。三曰筋极，令人数转筋，十指爪甲皆
痛，苦倦不能久立。四曰骨极，令人酸削，齿苦痛，手足烦疼，不可以立，不欲行动。
五曰肌极，令人羸瘦无润泽，饮食不生肌肉。六曰精极，令人少气，吸吸然内虚，
五脏不足，发毛落，悲伤喜忘。
七伤者∶一曰大饱伤脾，脾伤善噫，欲卧，面黄。二曰大怒逆气伤肝，肝伤少气，目暗。
三曰强力举重，久坐湿地伤肾，肾伤少精，腰背痛，厥逆下冷。四曰形寒寒饮伤肺，肺伤少
气，咳嗽，鼻鸣。五曰忧愁思虑伤心，心伤苦惊，喜忘喜怒。六曰风雨寒暑伤形，形伤发肤
枯夭。七曰大恐惧不节伤志，志伤恍惚不乐。又曰∶七伤者，一曰阴寒，二曰阴痿，三曰里
急，四曰精寒，五曰精少，阴下湿，六曰精清，七曰小便苦数，临事不举。
王节斋曰∶人若色欲过度，伤损精血，必生阴虚火动之病。睡中盗汗，午后发热，咯咯
咳嗽，倦怠无力，饮食少进，甚则痰涎带血，或咳血，吐血，衄血，身热脉沉数，肌肉消瘦
，此名劳瘵，最为难治，轻者用药数十服，重者期以岁年。然必须病患惜命，坚心定志，绝
房室，息妄想，戒恼怒，节饮食，以自培其根，此谓内外交治，庶可保全。
薛立斋曰∶劳瘵之证，大抵属足三阴亏损，虚热无火之证，故昼发夜止，夜发昼止，不
时而作。当用六味地黄丸为主，以补中益气汤调补脾胃。若脾胃先损者，当以补中益气汤为
主，以六味地黄温存肝肾，多有得生者。若误用黄柏、知母之类，则复伤脾胃，饮食日少，
诸脏愈虚，元气下陷，腹痞作泻，则不可救矣。夫衄血吐血之类，因虚火妄动，血随火而泛
行，或阳气虚，不能摄血归经而妄行，其脉弦洪，乃无根之火浮于外也。大抵此证多因火土
太旺，金水衰涸之际，不行保养，及三冬火气潜藏，不远帏幕，戕贼真元，故至春
末夏初，患头疼脚软，食少体热，而为注夏之病。或少有老态，不耐寒暑，不胜劳役，四时
迭病，此因气血方长而劳心亏损，精血未满而早为斫丧，故其见证难以名状。若左尺脉
虚弱或细数，是左肾之真阴不足也，用六味丸。右尺脉迟软，或沉细而数欲绝，是命门之相
火不足也，用八味丸。至于两尺微弱，是阴阳俱虚也，用十补丸。此皆滋其化源也，仍须
参前后发热、咳嗽诸证治之。
《难经》说：损脉导致的疾病是怎样的呢？回答说：第一损，损伤在皮毛，表现为皮肤聚集而毛发脱落。第二损，损伤在血脉，血脉虚弱稀少，不能滋养五脏六腑。第三损，损伤在肌肉，肌肉消瘦，饮食无法转化为肌肤营养。第四损，损伤在筋，筋脉松弛，不能自主收持肢体。第五损，损伤在骨，骨痿软弱，不能起床。与此相反的情况，是至脉（极度虚损）的疾病。病势从上往下发展的，出现骨痿不能起床的会死亡；病势从下往上发展的，出现皮聚毛落的会死亡。治疗损证的方法：肺受损的，补益其气。心受损的，调和其营卫。脾受损的，调节饮食，适应寒温变化。肝受损的，舒缓其中焦之气。肾受损的，补益其精，这就是治疗损证的方法。如果不能治疗其虚损，还谈得上其他什么呢？所以说：实证用泻法使实更实，虚证用补法使虚更虚，损害不足的正气而增加有余的邪气，这是中等水平医生造成的危害。
（张介宾）按语：上述关于上损和下损的说法，义理极其精妙，但还有未尽之处，应当详尽说明。大凡因思虑、劳倦、外感等病症则损伤阳气，损伤阳气的，疾病必然从上往下发展；因色欲、醉饱、内伤等病症则损伤阴精，损伤阴精的，疾病必然从下往上发展。如《内经》所说：“二阳（胃与大肠）的病发于心脾，有难以启齿的隐情，女子月经闭止”之类，这就是从上往下的例子。又《内经》说：“五脏主藏精，不可损伤，损伤则失守而阴虚，阴虚则无气，无气就会死亡”，这就是从下往上的例子。大凡从上往下发展的，先损伤气。所以第一损损伤肺，病在声音气息和肤表腠理；第二损损伤心，病在血脉和面色；第三损损伤胃，病在饮食不调；第四损损伤肝，病为抽搐疼痛；第五损损伤肾，病为骨痿、大小便失禁。这是先伤阳气，而后波及阴精，阳气竭于下，则孤阴无法独自存在，就无法救治了。从下往上发展的，先损伤精。所以第一损损伤肾，病为源泉干涸；第二损损伤肝，病为血动筋枯；第三损损伤脾，病为痰涎壅盛；第四损损伤心，病为神魂失守；第五损损伤肺，病为喘急短气。这是先伤阴精，而后波及阳气，阴精竭于上，则孤阳无法独自生存，就无法救治了。所以说：心肺受损则神气衰败，肝肾亏损则形体敝坏，脾胃受损则饮食不能化为血气。凡是明智的人，就应当考察病因，预防其萌芽，又有什么虚损可忧虑的呢？如果等到源流都枯竭了，才归罪于药物无效、医生不好，这也太愚蠢了。
《巢氏病源》说：所谓的虚劳，就是五劳、七伤、六极。一是志劳，二是思劳，三是心劳，四是忧劳，五是瘦劳。又有肺劳，表现为短气且面部浮肿，鼻子闻不到香臭。肝劳，表现为面目干枯黑黄，口苦，精神不守，恐惧害怕不能独卧，视物不明。心劳，表现为恍惚健忘，大便困难，有时像鸭粪一样稀溏，口中生疮。脾劳，表现为舌根僵硬，不能吞咽唾液。肾劳，表现为背部难以俯仰，小便不利，颜色赤黄且有淋漓不尽，阴茎内部疼痛，阴囊潮湿生疮，小腹胀满急迫。六极中，一是气极，使人内脏空虚，五脏不足，邪气多正气少，不想说话。二是血极，使人面色无华，眉毛头发脱落，恍惚健忘。三是筋极，使人频繁抽筋，十个手指和指甲都痛，痛苦疲倦不能久站。四是骨极，使人身体酸削，牙齿痛苦，手足烦疼，不能站立，不想活动。五是肌极，使人羸瘦没有润泽，饮食不能生成肌肉。六是精极，使人气短，呼吸浅促内脏空虚，五脏不足，毛发脱落，悲伤健忘。
七伤中：一是大饱伤脾，脾伤容易嗳气，想躺卧，面色发黄。二是大怒导致气逆伤肝，肝伤气少，目暗不明。三是强力举重，久坐湿地伤肾，肾伤精少，腰背痛，四肢厥冷下焦寒冷。四是身体受寒、喝冷饮伤肺，肺伤气少，咳嗽，鼻鸣。五是忧愁思虑伤心，心伤易惊恐，喜忘喜怒无常。六是风雨寒暑伤害形体，形体受伤导致皮肤枯槁夭折。七是大恐惧不节制伤志，志伤表现为恍惚不乐。又说：七伤还包括：一是阴寒，二是阳痿，三是里急，四是精寒，五是精少，阴部潮湿，六是精液清稀，七是小便频数痛苦，行房时勃起功能障碍。
王节斋说：人如果色欲过度，损伤精血，必定产生阴虚火动的病证。睡中盗汗，午后发热，咯咯咳嗽，倦怠无力，饮食减少，甚至痰中带血，或咳血、吐血、衄血，身热脉沉数，肌肉消瘦，这名叫劳瘵，最为难治，轻者用药数十服，重者以年为单位计算病程。然而必须病人爱惜生命，坚定心志，断绝房事，平息妄想，戒除恼怒，节制饮食，来培养自己的根本，这叫内外兼治，才可以保全性命。
薛立斋说：劳瘵的证候，大体属于足三阴亏损，是虚热无火的证候，所以白天发作晚上停止，晚上发作白天停止，不时发作。应当用六味地黄丸为主，配合补中益气汤调补脾胃。如果脾胃先受损的，应当以补中益气汤为主，配合六味地黄丸温养肝肾，多有获救的。如果误用黄柏、知母之类的药，则会再次损伤脾胃，饮食日渐减少，各脏腑更加虚弱，元气下陷，腹部痞满作泻，那就不可救治了。至于衄血、吐血之类，是因为虚火妄动，血随火气泛滥运行，或者阳气虚弱，不能摄血归经而妄行，其脉象弦洪，是无根之火浮越于外。大体这类病证多因火土太旺，金水衰涸之际，不注意保养，以及冬季火气潜藏时，不远离女色，戕害真元，所以到春末夏初，患头痛脚软，食少体热，成为注夏之病。或者稍显老态，不耐寒暑，不胜劳役，四季交替生病，这是因为气血正在生长却劳心亏损，精血未满却过早耗损，所以见证难以名状。如果左尺脉虚弱或细数，是左肾真阴不足，用六味地黄丸。右尺脉迟软，或沉细而数欲绝，是命门相火不足，用八味地黄丸。至于两尺脉微弱，是阴阳俱虚，用十补丸。这些都是滋生化之源，仍需参考之前的发热、咳嗽等证候进行治疗。
The *Nan Jing* (Classic of Difficult Issues) states: What are the diseases caused by the Sun (Damaged) pulse? The answer is: First damage affects the skin and hair, manifesting as gathered skin and falling hair. Second damage affects the blood vessels, where the vessels are deficient and scanty, unable to nourish the five zang organs and six fu organs. Third damage affects the muscles, resulting in emaciation, where food and drink cannot transform into flesh. Fourth damage affects the sinews, causing flaccidity and inability to hold or control the limbs. Fifth damage affects the bones, leading to bone atrophy and inability to rise from bed. The reverse of this describes the disease of the Zhi (Extreme) pulse. If the disease progresses from top to bottom, death occurs when bone atrophy prevents rising from bed; if it progresses from bottom to top, death occurs when skin gathers and hair falls. The method for treating damage is: For lung damage, benefit its qi. For heart damage, regulate its Ying and Wei (nutritive and defensive qi). For spleen damage, regulate diet and adapt to cold and warmth. For liver damage, soothe its interior. For kidney damage, benefit its essence. This is the method for treating damage. If one cannot treat the deficiency, how can one discuss anything else? Thus it is said: Treating excess with reducing methods makes excess more excessive, and treating deficiency with tonifying methods makes deficiency more deficient; damaging the insufficient and benefiting the redundant—this is the harm caused by average physicians.
Zhang Jiebin adds: The above discussion on upper and lower damage has extremely refined principles, yet there are incomplete aspects that should be fully explained. Generally, conditions such as overthinking, fatigue, and external pathogens injure Yang; injuries to Yang result in disease progressing from top to bottom. Conditions such as sexual indulgence, overeating, drinking, and internal injury injure Yin; injuries to Yin result in disease progressing from bottom to top. As the Classics state: "Diseases of the Two Yang (Stomach and Large Intestine) originate in the Heart and Spleen, involving unspoken difficulties, and in women, amenorrhea." This is an example of progression from top to bottom. Again, the Classics state: "The five zang organs store essence and must not be injured; injury leads to loss of control and yin deficiency; yin deficiency leads to lack of qi; lack of qi leads to death." This is an example of progression from bottom to top. Disease progressing from top to bottom first injures Qi. Thus, first damage to the Lung manifests as disorders of voice, respiration, skin, and pores; second damage to the Heart manifests as disorders of blood vessels and complexion; third damage to the Stomach manifests as dietary irregularities; fourth damage to the Liver manifests as spasms and pain; fifth damage to the Kidney manifests as bone atrophy and incontinence of urine and feces. This is first injuring Yang, then affecting Yin; if Yang exhausts at the bottom, isolated Yin cannot survive alone, and it is incurable. Disease progressing from bottom to top first injures Essence. Thus, first damage to the Kidney manifests as dried-up sources; second damage to the Liver manifests as restless blood and withered sinews; third damage to the Spleen manifests as abundant phlegm and saliva; fourth damage to the Heart manifests as loss of spirit and mind control; fifth damage to the Lung manifests as panting and shortness of breath. This is first injuring Yin, then affecting Yang; if Yin exhausts at the top, isolated Yang cannot generate alone, and it is incurable. Therefore, it is said: Damage to the Heart and Lung leads to decline of Shen (Spirit); deficiency of the Liver and Kidney leads to deterioration of form; damage to the Spleen and Stomach leads to food and drink failing to transform into blood and qi. Wise individuals should investigate the causes and prevent the onset gradually; why worry about deficiency damage? If one waits until both source and flow are exhausted before blaming ineffective medicine or poor medical skill, this is extreme foolishness.
The *Chao Shi Bing Yuan* (Source of Diseases of Chao Yuanfang) states: Xu Lao (Deficiency Consumption) refers to Wu Lao (Five Labors), Qi Shang (Seven Injuries), and Liu Ji (Six Extremes). One is Zhi Lao (Labor of Will), two is Si Lao (Labor of Thought), three is Xin Lao (Labor of Heart), four is You Lao (Labor of Worry), five is Shou Lao (Labor of Emaciation). There is also Fei Lao (Lung Labor), characterized by shortness of breath and facial edema, and loss of smell. Gan Lao (Liver Labor) is characterized by dry, dark face and eyes, bitter taste, unsettled spirit, fearfulness preventing solitary sleeping, and blurred vision. Xin Lao (Heart Labor) is characterized by mental confusion and forgetfulness, difficult defecation or loose stools like duck dung, and mouth sores. Pi Lao (Spleen Labor) is characterized by a stiff tongue base and inability to swallow saliva. Shen Lao (Kidney Labor) is characterized by difficulty bending and extending the back, dysuria, reddish-yellow urine with dribbling, internal penile pain, damp scrotum with sores, and fullness/urgency in the lower abdomen. Regarding Liu Ji (Six Extremes): One is Qi Ji (Extremity of Qi), causing internal emptiness, deficiency of the five zang organs, excess of pathogenic factors, scarcity of healthy qi, and reluctance to speak. Two is Xue Ji (Extremity of Blood), causing lack of color, falling eyebrows and hair, mental confusion, and forgetfulness. Three is Jin Ji (Extremity of Sinews), causing frequent muscle cramps, pain in all ten fingers and nails, and debilitating fatigue preventing prolonged standing. Four is Gu Ji (Extremity of Bones), causing soreness and wasting, painful teeth, vexing pain in hands and feet, inability to stand, and reluctance to move. Five is Ji Ji (Extremity of Muscle), causing emaciation without luster, and food failing to generate muscle. Six is Jing Ji (Extremity of Essence), causing shortness of breath, shallow internal breathing, emptiness of the five zang organs, falling hair, sadness, and forgetfulness.
Regarding Qi Shang (Seven Injuries): One is excessive fullness injuring the Spleen, causing belching, desire to lie down, and yellow complexion. Two is great anger causing rebellious qi to injure the Liver, causing scanty qi and dim vision. Three is strenuous lifting or sitting long on wet ground injuring the Kidney, causing scanty essence, lower back pain, and cold extremities/jiao. Four is cold exposure and cold drinks injuring the Lung, causing scanty qi, cough, and nasal resonance. Five is sorrow and overthinking injuring the Heart, causing fright, forgetfulness, and emotional instability. Six is wind, rain, cold, and heat injuring the Form, causing withered and premature aging of skin and hair. Seven is great fear without moderation injuring Zhi (Will), causing mental vagueness and unhappiness. It is also said: Seven Injuries include: One is Yin Cold, two is Yin Impotence, three is Li Ji (Internal Urgency), four is Jing Han (Cold Essence), five is Jing Shao (Scant Essence) with damp genitals, six is Jing Qing (Clear Essence), seven is Ku Shu (Painful Frequency) of urination and failure to perform during intercourse.
Wang Jiezhai states: If one indulges excessively in sexual desires, damaging essence and blood, one will inevitably develop Bing Zheng (Pathological Conditions) of Yin Deficiency with Fire Hyperactivity. Symptoms include night sweats during sleep, afternoon fever, hacking cough, fatigue and weakness, reduced appetite, and in severe cases, blood-streaked sputum, hemoptysis, hematemesis, epistaxis, body heat with deep and rapid pulse, and muscle emaciation. This is named Lao Zhai (Consumptive Disease), which is the most difficult to treat. Mild cases require dozens of doses of medicine; severe cases take years. However, the patient must cherish life, strengthen their resolve, abstain from sexual activity, cease delusional thoughts, avoid anger, and regulate diet to cultivate their root. This is called internal and external combined treatment, which may preserve life.
Xue Lizhai states: The syndrome of Lao Zhai generally belongs to deficiency of the Foot Three Yin meridians, presenting as deficiency heat without fire, thus occurring during the day and stopping at night, or vice versa, appearing intermittently. One should primarily use Liu Wei Di Huang Wan (Six-Ingredient Pill with Rehmannia) to tonify, and Bu Zhong Yi Qi Tang (Decoction for Supplementing the Middle and Augmenting the Qi) to regulate and tonify the Spleen and Stomach. If the Spleen and Stomach are damaged first, one should primarily use Bu Zhong Yi Qi Tang, supplemented by Liu Wei Di Huang Wan to gently warm the Liver and Kidney; many patients recover. If one mistakenly uses herbs like Huang Bo (Phellodendron Bark) and Zhi Mu (Anemarrhena Rhizome), it further damages the Spleen and Stomach, reduces food intake daily, increases deficiency in all organs, causes sinking of Yuan Qi (Original Qi), abdominal distension, and diarrhea, rendering it incurable. As for epistaxis and hematemesis, these occur because deficiency fire moves recklessly, carrying blood along with it to flow erratically, or because Yang Qi is deficient and cannot hold blood within the vessels, causing it to bleed randomly. The pulse is wiry and flooding, indicating rootless fire floating outward. Generally, this condition arises when Fire and Earth are too strong while Metal and Water are depleted, due to lack of maintenance, and especially during winter when fire qi hides but one does not avoid sexual intimacy, damaging true Yuan Qi. Thus, in late spring and early summer, one suffers headache, weak legs, poor appetite, and body heat, developing Zhu Xia (Summer Malady). Or, showing signs of premature aging, intolerance to cold and heat, and inability to bear labor, getting sick in every season. This is because Xin Qi (Heart Qi) was damaged by overwork while blood and qi were still growing, and Jing Xue (Essence and Blood) was squandered prematurely before full maturity, making the manifestations hard to describe. If the Left Chi (Cunian) pulse is weak, fine, or rapid, it indicates insufficiency of True Yin in the Left Kidney; use Liu Wei Di Huang Wan. If the Right Chi pulse is slow and soft, or deep, fine, and nearly imperceptible, it indicates insufficiency of Ministerial Fire in the Ming Men (Gate of Life); use Ba Wei Di Huang Wan (Eight-Ingredient Pill with Rehmannia). If both Chi pulses are weak, it indicates dual deficiency of Yin and Yang; use Shi Bu Wan (Ten-Increment Pill). These all nourish the source of transformation, but one must still treat based on previous symptoms of fever and cough.