丹溪曰∶经水者阴血也，阴必从阳，故其色红，禀火色也。血为气之配，气热则热，气
寒则寒，气升则升，气降则降，气凝则凝，气滞则滞，气清则清，气浊则浊。上应于月，其
行有常，名之曰经。为气之配，因气而行。成块者，气之凝也；将行而痛者，气之滞也；来
后作痛者，气血俱虚也；色淡者，亦虚也，而有水混之也；错经妄行者，气之乱也；紫者气
之热也，黑者热之甚也。今人但见其紫者、黑者、作痛者、成块者，率指为风冷，而行温热
之剂，则祸不旋踵矣。良由《病源》论月水诸病，皆曰风冷乘之，宜其相习而成俗也。或曰∶
黑者，北方水色也，紫淡于黑，非冷而何？予曰∶经云亢则害，承乃制，热甚者必兼水化，
所以热则紫，甚则黑也。况妇人性执而见鄙，嗜欲加倍，脏腑厥阳之火，无日不起，非热而
何？若曰风冷，必须外得，设或有之，盖千百而一二也。
准绳云∶冷症外邪初感，入经必痛。或不痛者，久则郁而变热矣。且寒则凝，即行
而紫黑，故非寒也。（二公之说甚明）
叶氏曰∶血黑属热，丹溪之论善矣。然风寒外乘者，十中常见一二，何以辨之？盖寒主
引涩，小腹内必时常冷痛，经行之际，或手足厥冷，唇青面白，尺脉或迟或微或虚，或虽大
而必无力；热则尺脉或洪或数或实，或虽小而必有力，于此审之，可以得其情矣。（脉症相参，尤为的确）
李氏曰∶心主血，故以色红为正，虽不对期而色正者易调。其色紫者风也，黑者热甚也
；淡白者虚也，或挟痰停水以混之也；如烟尘水，如屋漏水，如豆汁，或带黄混浊模糊者，
湿痰也；成块作片，血不变者，气滞也，或风冷乘之也；色变紫黑者，血热也。大概紫者，
四物汤加防风、白芷、荆芥；黑者，四物汤加芩、连、香附；淡白者，芎归汤加参、 、白
芍药、香附；有痰者，二陈汤加芎、归；如烟尘者，二陈汤加秦艽、防风、苍术；如豆汁者
，四物汤加芩、连；成块者，四物汤加香附、玄胡索、枳壳、陈皮，随症选用。
朱丹溪说：月经是阴血，阴必须依附于阳，所以它的颜色是红色的，这是禀受了火的色泽。血是气的配偶（配合物），气热则血热，气寒则血寒，气升则血随气上升，气降则血随气下降，气凝滞则血凝滞，气郁结则血郁结，气清则血清，气浊则血浊。月经在天上对应月亮，其运行有固定的规律，所以称为“经”。因为它是气的配偶，所以随着气的变化而运行。形成血块的，是气机凝滞所致；即将行经时感到疼痛的，是气机郁滞所致；行经结束后才感到疼痛的，是气血两虚所致；颜色淡的，也是虚证，但有水湿混杂其中；经血妄行、不按周期来的，是气机紊乱所致；颜色紫的，是气热所致；颜色黑的，是热势极盛所致。现在的人只看到经血颜色紫、黑，或者伴有疼痛、成块的，就一概认为是风冷侵袭，从而使用温热的药物，这样灾祸很快就会降临。这主要是由于《诸病源候论》在论述月经各种疾病时，都说是风冷乘虚侵袭，难怪人们习以为常，形成了这种习俗。有人问：黑色是北方水的颜色，紫色比黑色淡一些，难道不是寒冷吗？我说：医经中说“亢盛则有害，承制才能平衡”，热势极盛时必然兼有水化的表现，所以热则色紫，热极则色黑。况且妇人性情固执且见识浅陋，嗜欲加倍，脏腑中厥阳之火，没有一天不升起，这难道不是热证吗？如果说的是风冷，那必须是外感得来的，即使有这种情况，大概也是千中一二罢了。
王肯堂《医学准绳六要》说：如果是冷症，初感外邪，侵入经脉必定疼痛。如果不痛的，时间久了就会郁结而化热。而且寒性凝滞，如果行经时出现紫黑色，那并不是寒证。（这两位先生的说法非常明白透彻）
叶氏说：经血发黑属于热证，朱丹溪的论述很好。然而风寒外袭的情况，十个人中常见一两个，如何辨别呢？大抵寒邪主收引涩滞，小腹内部必定时常冷痛，行经期间，或者手足冰冷，嘴唇青紫、面色苍白，尺脉或迟、或微、或虚，或者虽然脉大但必定无力；热证则尺脉或洪、或数、或实，或者虽然脉小但必定有力，从这里仔细审察，就可以得到病情的真相了。（脉象与症状相互参照，尤为确切）
李氏说：心主血脉，所以红色是正常的，即使月经不对期来潮，但颜色正常的也容易调理。颜色紫的是风邪所致，颜色黑的是热势极盛；颜色淡白的是虚证，或者夹杂痰饮、停水混杂其中；像烟尘一样的水样经血，像屋顶漏下来的雨水，像豆汁一样的，或者是带有黄色、混浊模糊的，是湿痰所致；形成血块成片，血液本身性质未变的，是气机郁滞，或者是风冷侵袭所致；颜色变为紫黑的，是血热所致。大抵颜色紫的，用四物汤（补血调经基础方）加防风、白芷、荆芥；颜色黑的，用四物汤加黄芩、黄连、香附；颜色淡白的，用芎归汤（川芎、当归组成）加人参、[此处原文缺字，通常指黄芪或白术等补气药，依语境补全逻辑]、白芍药、香附；有痰的，用二陈汤（燥湿化痰基础方）加川芎、当归；像烟尘样的，用二陈汤加秦艽、防风、苍术；像豆汁样的，用四物汤加黄芩、黄连；成块的，用四物汤加香附、玄胡索、枳壳、陈皮，根据症状选用。
Zhu Danxi stated: Menstrual blood is Yin blood. Yin must follow Yang; therefore, its color is red, inheriting the hue of Fire. Blood is the companion of Qi. If Qi is hot, blood becomes hot; if Qi is cold, blood becomes cold. If Qi ascends, blood ascends; if Qi descends, blood descends. If Qi stagnates, blood coagulates; if Qi is obstructed, blood is blocked. If Qi is clear, blood is clear; if Qi is turbid, blood is turbid. Corresponding to the moon in heaven, its flow follows a regular pattern, hence it is named "Jing" (Menses). As the companion of Qi, it moves with Qi. The formation of clots is due to Qi stagnation. Pain occurring just before menstruation is due to Qi obstruction. Pain occurring after menstruation is due to deficiency of both Qi and Blood. A pale color indicates deficiency, often mixed with dampness/water. Irregular or profuse bleeding is due to Qi disorder. A purple color indicates Qi heat, while a black color indicates extreme heat. Nowadays, people only see purple or black blood, pain, or clots, and generally attribute them to Wind-Cold invasion, administering warm and hot remedies. This leads to disaster almost immediately. This error stems from *Zhubing Yuanhou Lun* (The Source and Characteristics of All Diseases), which attributes all menstrual disorders to Wind-Cold invasion. No wonder this has become a common practice. Some ask: Black is the color of Water in the North; purple is lighter than black. Is it not cold? I say: The medical classics state, "When things reach an extreme, they cause harm; only through control can balance be maintained." Extreme heat necessarily incorporates the transformation of Water. Thus, heat results in purple, and extreme heat results in black. Moreover, women are often stubborn and their insights limited, with doubled desires. The Fire of Jue-Yang (Defiant Yang) in their Zang-Fu organs rises daily. How can this not be Heat? If it were Wind-Cold, it must be externally acquired. Even if such cases exist, they are rare, perhaps one in a thousand.
Wenken Tang's *Yixue Zhunsheng Liuyao* states: In Cold syndromes, when external pathogens are initially contracted and enter the meridians, pain is inevitable. If there is no pain, stagnation will eventually transform into Heat. Since Cold causes coagulation, if the blood is purple or black during flow, it is not Cold. (The explanations of these two masters are very clear.)
Ye Shi said: Black blood belongs to Heat; Zhu Danxi's discussion is excellent. However, cases of external Wind-Cold invasion are seen in one or two out of ten. How can they be distinguished? Generally, Cold governs contraction and astringency. There must be frequent cold pain in the lower abdomen. During menstruation, the hands and feet may be cold, the lips cyanotic, and the face pale. The Chi pulse (at the wrist) may be slow, faint, or deficient, or even if large, it must be forceless. In Heat syndromes, the Chi pulse may be surging, rapid, or full, or even if small, it must be forceful. By examining these aspects, the true nature of the condition can be ascertained. (Correlating pulse and symptoms is particularly accurate.)
Li Shi said: The Heart governs Blood, so red is the correct color. Even if the cycle is irregular, if the color is normal, it is easy to treat. Purple color indicates Wind; black indicates extreme Heat; pale white indicates Deficiency, possibly mixed with Phlegm or retained water. Blood resembling smoke/dust water, roof leak water, or bean juice, or yellow and turbid/muddy, indicates Damp-Phlegm. Clots forming sheets where the blood itself remains unchanged indicate Qi stagnation or Wind-Cold invasion. Color changing to purple-black indicates Blood Heat. Generally, for purple color, use Siwu Tang (Four Substances Decoction) added with Fangfeng (Saposhnikovia Root), Baizhi (Angelica Dahurica Root), and Jingjie (Schizonepeta Spike). For black color, use Siwu Tang added with Huangqin (Scutellaria Root), Lianzi (Coptis Rhizome), and Xiangfu (Cyperus Rhizome). For pale white color, use Xionggui Tang (Ligusticum and Angelica Decoction) added with Renshen (Ginseng Root), [text missing, likely Huangqi or Baizhu], Baishao (White Peony Root), and Xiangfu. For Phlegm, use Erchen Tang (Two-Aged Decoction) added with Chuanxiong (Ligusticum Chuanxiong Rhizome) and Danggui (Angelica Sinensis Root). For smoke-like appearance, use Erchen Tang added with Qinjiao (Gentiana Macrophylla Root), Fangfeng, and Cangzhu (Atractylodes Rhizome). For bean juice-like appearance, use Siwu Tang added with Huangqin and Huanglian. For clots, use Siwu Tang added with Xiangfu, Yuanshusu (Corydalis Rhizome), Zhike (Bitter Orange Fruit), and Chenpi (Tangerine Peel), selected according to symptoms.