波斯青黛。是外国蓝靛花。既不可得。则中国靛花亦可用。（濒湖） 真青黛形状。与
靛花不同类。今因其罕有。而靛花功效亦同。特假为名。旋收曝干。色甚紫碧。市家多取干
靛充卖。顾干靛枯黑重实。靛花娇嫩轻浮。亦殊易别。（仙制药性）
味咸甘平。气寒。专治小儿疳蚀羸瘦。发热疳痢。杀疳虫。并小儿丹毒。解诸热惊痫。 能
收五脏郁火。解热毒。泻肝消食积。（丹溪） 大略主治肝热。及解肺胃热。（嵩） 方书治
中
下及 疝。 一妇人脐腹上下。连二阴。遍生湿疮。状如马瓜疮。痒而痛。出黄汁。他处并
无。大小便涩。食亦减。身面微肿。医作恶疮治。用鳗鲡鱼松脂黄丹之药涂之。热痛甚。询
知其人嗜酒。喜食鱼蟹发风等物。急令洗去其药。以马齿苋四两。杵烂。入青黛一两。
匀涂之。即时热减。痛痒皆去。仍以八正散日三服之。分败客热。药干即上。如此渐减。二
十日愈。此盖中下焦蓄风热毒瓦斯也。若不出。当作肠痈内痔。仍须禁酒色发风等物。（宗 ）
禀水土阴寒之气以生。又得土气之浓。故性味咸寒甘平而专解热毒。（仲淳） 心口热痛。
姜汁调一钱服之。肺热咯血。青黛一两。杏仁用牡蛎粉炒过一两。研匀。黄蜡化和。作三十
饼。每服一饼。以干柿半个夹定。湿纸裹。煨香嚼食。粥饮送下。日三服。
〔论〕草木之茎叶无弗青者。而兹物独显诸用。由蓝从春夏之交生苗。即以五六月结
实。
用。
谓
收
和之
用。
而真
曰收
火邪
与于
气。不等于香附青皮之疏泄。以能大布生阳之气以行也。何以为解毒的剂。曰。正气流
则邪气自然涣释也。何以于身半以上天气之治较多。曰。此正生阳之气化上达于天之征也
抑何以杀虫最效。曰
以滞血。此味以生阳
化为水乎。 又按蓝
直用蓝汁与板蓝根为
从胸前下至心经。两
死。又取蓝汁加麝香雄黄。更投一蛛。随化为水。因取其汁点于
征矣。
青黛治血分实热。若吐衄咯唾。由于阴虚阳越。火空上炎而发者。此味便非中的之剂。
临证
〔修治〕 但取淀桶中浮起者。晒干。用时水飞去脚。缘中有锻石。宜飞净服饵也。若
外敷
波斯青黛，是外国的蓝靛花。既然难以获得，那么中国的靛花也可以使用。（李时珍《本草纲目》）
真正的青黛形状与靛花不同类。如今因为真青黛罕见，而靛花的功效也相同，所以特别借用其名。将靛花迅速收割并晒干后，颜色非常紫碧。市场上很多人用干靛来冒充售卖。但是干靛枯黑、沉重结实，而靛花娇嫩、轻浮，也很容易辨别。（《雷公炮炙论》或相关制药性著作）
味道咸、甘，性质平；气寒。专门治疗小儿疳积蚀烂、身体消瘦、发热、疳痢，杀灭疳虫，以及小儿丹毒，解除各种热邪引起的惊痫。能够收敛五脏的郁火，解热毒，泻肝火，消除食积。（朱震亨《丹溪心法》）
方书中记载治疗中下焦及疝气。有一位妇女脐腹上下，连接两个阴部，遍生湿疮，形状像马瓜疮，又痒又痛，流出黄色汁液，其他部位没有，大小便涩滞，食欲减退，身面轻微浮肿。医生当作恶疮治疗，用鳗鲡鱼、松脂、黄丹等药物涂抹，导致热痛加剧。询问得知此人嗜酒，喜欢吃鱼蟹等发风之物。急忙令其洗去涂药，取马齿苋四两，捣烂，加入青黛一两，均匀涂抹。顿时热感减轻，疼痛瘙痒全部去除。随后每天服用三次八正散，以分消客热。药干即换，如此逐渐减少，二十天痊愈。这大概是中下焦蓄积了风热毒气。如果不排出，可能会发展成肠痈或内痔。仍然必须禁止饮酒、房事及食用发风之物。（陈藏器《本草拾遗》或类似医案记录）
禀受水土阴寒之气而生，又得到土气的浓厚滋养，所以性味咸寒甘平，专门解热毒。（缪希雍《本草经疏》）
心口热痛，用姜汁调服一钱青黛。肺热咯血，取青黛一两，杏仁一两（用牡蛎粉炒过），研匀，加黄蜡调和，制成三十个饼。每次服用一个饼，用半个干柿子夹住，用湿纸包裹，煨熟后嚼食，用粥饮送下，每天三次。
【论述】草木的茎叶无不呈青色，而此物独显其用途。因为蓝草从春夏之交生出苗芽，就在五六月间结实采收。所谓“收”，是指收敛火邪之气。不同于香附、青皮的疏泄作用，因为它能大布生发之阳气以运行。为什么它是解毒的确切药剂？回答是：正气流通，则邪气自然涣散。为什么在治疗上半身天气相关的病症较多？回答是：这正是生发之气化上达于天的征象。又为什么杀虫最有效？回答是：它能化解水湿，并用生阳之气化为水湿以行滞血。另外按语：蓝草直接取蓝汁与板蓝根使用，从胸前下行至心经，杀死一只蜘蛛，又取蓝汁加麝香、雄黄，再投入一只蜘蛛，随即化为水。因此取其汁液点涂……这是征验了青黛治血分实热。如果吐血、衄血、咯唾是由于阴虚阳越，火气空上炎而引发的，这种药便不是对症的确切药剂。
【修治】只取沉淀桶中浮起的部分，晒干。使用时用水飞法去掉底部的沉淀物，因为其中含有锻石，应当飞净后服用。如果是外用敷贴……
Persian Qingdai (Indigo Naturalis) is the indigo flower from foreign lands. Since it is difficult to obtain, Chinese indigo flowers can also be used. (Li Shizhen)
The shape of true Qingdai differs from that of indigo flowers. Currently, because true Qingdai is rare and the efficacy of indigo flowers is similar, its name is borrowed for convenience. After rapid harvesting and sun-drying, the color is very purple-green. Market vendors often use dried indigo paste to pass off as Qingdai. However, dried indigo is withered, black, heavy, and solid, whereas indigo flowers are tender and light; they are also easy to distinguish. (Pharmacopoeia on Processing Medicinal Substances)
It tastes salty and sweet, has a neutral nature, and is cold in qi. It specifically treats pediatric gan accumulation with erosion, emaciation, fever, gan dysentery, kills gan parasites, and addresses pediatric erysipelas (Dan Du). It resolves various heat-induced convulsions and epilepsy. It can collect stagnant fire in the five zang organs, resolve heat toxins, drain liver fire, and eliminate food stagnation. (Zhu Zhenheng)
Generally, it treats liver heat and resolves lung and stomach heat.
Medical texts record its use for middle and lower jiao disorders and hernias. A woman suffered from wet sores all over her abdomen below the navel, extending to both yin organs, resembling "horse melon sores." They were itchy and painful, exuding yellow fluid, with no other lesions elsewhere. Her urination and defecation were obstructed, and her appetite decreased. Her face and body were slightly swollen. The physician treated it as a malignant sore, applying remedies containing eel, pine resin, and red lead, which intensified the heat and pain. Upon inquiry, it was learned that she loved alcohol and enjoyed eating fish, crabs, and other "wind-inducing" foods. She was urgently instructed to wash off the applied medicine. Four taels of purslane (Portulaca oleracea) were mashed, mixed with one tael of Qingdai, and evenly applied. The heat immediately subsided, and pain and itching ceased. Thereafter, Bazheng San (Eight-Ingredient Decoction for Rectifying the Righteous) was administered three times daily to dissipate external heat. As the dressing dried, it was replaced. Gradually reducing the dosage, she recovered in twenty days. This was likely due to the accumulation of wind-heat toxins in the middle and lower jiao. If not expelled, it might develop into intestinal abscess or internal hemorrhoids. Alcohol, sexual activity, and wind-inducing foods must still be strictly avoided. (Chen Cangqi)
Born from the yin-cold qi of water and earth, and enriched by the dense qi of earth, its nature and taste are salty, cold, sweet, and neutral, specializing in resolving heat toxins. (Miao Xiong)
For heat-pain in the heart and epigastrium, mix one qian of Qingdai with ginger juice and take orally. For hemoptysis due to lung heat, take one liang of Qingdai and one liang of Almond Seed (Xingren), stir-fried with Oyster Shell powder. Grind them together uniformly, mix with yellow beeswax, and form thirty pills. Take one pill per dose, sandwiched between half a dried persimmon, wrapped in wet paper, roasted until fragrant, chewed, and swallowed with congee broth. Administer three times daily.
[Discussion] The stems and leaves of herbs and trees are invariably green, yet this substance alone demonstrates specific utility. Indigo plants sprout between spring and summer and bear fruit in the fifth and sixth lunar months. The term "collect" refers to gathering the qi of fire pathogens. Unlike the dispersing and draining actions of Cyperi Rhizoma (Xiangfu) and Tangerine Peel (Qingpi), it greatly disseminates the qi of generating yang to facilitate movement. Why is it an accurate agent for detoxification? Because when righteous qi flows smoothly, pathogenic qi naturally dissipates. Why is it more frequently used for conditions related to heavenly qi in the upper half of the body? Because this is precisely the sign of generating qi transforming and ascending to heaven. Furthermore, why is it most effective at killing insects? Because it transforms dampness into water and uses generating yang qi to move stagnant blood. Additionally, regarding Indigo: Directly using indigo juice or Isatidis Radix (Banlangen) from the chest down to the Heart Meridian killed a spider. Adding musk and realgar to indigo juice and injecting another spider caused it to dissolve into water. Thus, taking its juice for topical application... serves as evidence.
Qingdai treats excess heat in the blood level. However, if vomiting blood, epistaxis, or spitting blood results from yin deficiency with yang hyperactivity, where fire flares upward due to emptiness, this herb is not the precise对症 agent.
[Processing] Only take the portion floating in the sedimentation vat, dry it in the sun. When used, remove the bottom sediment via water levigation (flying method) because it contains lime (calcined stone); it should be levigated cleanly before oral administration. For external application...