人之一生，气充于外，血附于内，阴阳和平，荣卫通调，何吐血之有？惟大怒、大劳，或过思、过虑，
伤其经络，逆其气机，致阴阳血气失其循行之常度，则血外溢，而有吐血之病矣。血虽同，而血之根由不同，
有胞中血海之血，有心包脾络之血。夫胞中为血海，其血热肉充肤，淡渗皮毛，若大怒、大劳，气虚一时，
不能摄血，致胞中之血不充于肤腠，反从气冲而上涌于胃脘。吐此血者，其血必多。治之之法，当调其荣卫，
和其三焦，使三焦之气和于荣卫，荣卫之气下合胞中，气归血附，即引
血归经之法也。若不按经调治，只期速效，妄称火盛血淫，骤用清凉泻火以止血，不但血不能即止，必增咳嗽
之病矣。夫吐血自有止期，虚痨咳嗽，必至丧身而后已。其心包之血，内包心，外通脉，下合肝。合肝者，肝
与心包皆为厥阴，同一气也。若房劳过度，思虑伤神，则吐心包之血。吐此血者，十无一生，惟药不妄投，大
补心肾，重服人参，可十全一二。其有身体不劳，内无所损，卒然哈血数口，或紫或红，一哈便出，此为脾络之
血。脾之大络，络于周身，络脉不与经脉和谐，则有此血。下不伤阴，内不伤经，此至轻至浅之血，不药亦
愈。若不分轻重，概以吐血之法治之，致络脉寒凝，变生他病，医之过也。又五脏有血，六腑无血。吐心脏之血
者，一二口即死；吐肺脏之血者，形如血丝；吐肾脏之血者，形如赤豆，五七日间必死；若吐肝脏之血，有生有
死，贵乎病者能自养，医者善调治尔；脾脏之血若罗络，即前哈血是也。凡吐血多者，乃胞中血海之血，医者学
不明经，指称胃家之血。夫胃为仓廪之官，受盛水谷，并未有血，谓血从胃出则可，若谓胃中有血，则不可也。
人的一生，气充盈于体表，血依附于体内，阴阳平和，营卫（运行于脉外之气与行于脉中之血）通畅协调，怎么会有吐血呢？只有在大怒、过度劳累，或者思虑过多、忧虑过度的情况下，损伤了经络，逆乱了气机，导致阴阳气血失去了正常运行的规律，血液就会向外溢出，从而产生吐血的病症。
虽然都是血，但血的来源根本不同，有来自胞中血海（女子胞及冲任二脉汇聚之处，为血之海）的血，有心包脾络（心包络与脾之大络）的血。
所谓胞中是血海，其血能滋润肌肉、充实皮肤、淡渗皮毛。如果遭遇大怒或大劳，导致气暂时虚弱，不能统摄血液，致使胞中的血不能充盈于肌肤腠理，反而随着气冲脉上涌至胃脘。吐出这种血的人，血量必然很多。治疗的方法，应当调理营卫，调和三焦（人体上、中、下三部的气化功能），使三焦之气与营卫和谐，营卫之气下行合于胞中，气归附于血，这就是所谓的“引血归经”的治疗方法。如果不按照经络理论进行调治，只追求速效，妄称是火盛血淫（火热亢盛导致血液妄行），突然使用清凉泻火的药物来止血，不但血不能立即止住，一定会增加咳嗽的病症。
吐血自有其停止的时候，如果是虚劳咳嗽，必定会导致丧命才停止。
至于心包的血液，内包护心脏，外通血脉，下合于肝。之所以说下合于肝，是因为肝与心包都属于厥阴经，具有相同的气机属性。如果是房事过度，思虑伤神，则会吐出心包的血液。吐出这种血的人，十个人中没有一个是能活下来的，除非用药不妄投，大补心肾，重用服用人参，或许能挽回一二成生机。
那些身体没有劳累，内部没有损耗，突然咳出几口血，颜色或紫或红，一咳就出来，这是脾络的血。脾的大络脉联络周身，如果络脉与经脉不和谐，就会出现这种出血。这种情况下部不伤阴，内部不伤经脉，是最轻微浅表的出血，不吃药也能痊愈。如果不分辨轻重，一概用治疗吐血的方法来对待，导致络脉寒凝，变生其他疾病，这是医生的过错。
另外，五脏有血，六腑无血。吐出心脏之血的，一两口就会死亡；吐出肺脏之血的，形状像丝线；吐出肾脏之血的，形状像赤豆，五到七天内必定死亡；如果吐出肝脏之血，有生也有死，关键在于病人能否自我调养，医生能否善于调治罢了；脾脏之血若涉及罗络（指脾之大络散布于体表），就是前面所说的咳血情况。
凡是吐血量多的，乃是胞中血海的血液，医生如果学问不明晓经典，会错误地指称为胃家的血。胃作为仓廪之官，负责接受和盛纳水谷，本身并没有血，说血从胃里出来是可以的，如果说胃里面有血，那就是不对的了。
Throughout a person's life, Qi (Vital Energy) is abundant on the exterior, while Blood adheres to the interior. When Yin and Yang are in harmony, and Ying-Wei (Nutritive and Defensive Qi/Blood) flow smoothly, how could hematemesis occur? Only when subjected to great anger, excessive labor, or overthinking and excessive worry, the meridians and collaterals are damaged, and the mechanism of Qi movement is reversed. This causes Yin-Yang, Blood, and Qi to lose their normal course of circulation, leading to blood overflowing outward and resulting in the disease of hematemesis.
Although it is all blood, the root sources differ. There is blood from the Chong Sea (the Sea of Blood located in the uterus/abdomen), and blood from the Pericardium and Spleen collaterals. The Chong Sea is the Sea of Blood; its blood nourishes muscles, fills the skin, and permeates the hair follicles. If one experiences great anger or excessive labor, Qi becomes temporarily deficient and fails to control the blood. Consequently, the blood from the Chong Sea fails to fill the skin and interstices but instead surges upward via the Chong Meridian to the epigastrium. Those who vomit this type of blood will have a large volume of blood. The treatment method should regulate Ying-Wei and harmonize the Sanjiao (Triple Burner). By making the Qi of the Sanjiao harmonious with Ying-Wei, and allowing Ying-Wei Qi to descend and merge with the Chong Sea, Qi returns to adhere to Blood. This is the method of "guiding blood back to its vessels." If one does not treat according to the meridians, seeking only rapid effects, and falsely attributes it to Excess Fire causing Blood Hyperactivity, suddenly using cooling and purgative herbs to stop bleeding will not only fail to stop the blood immediately but will also likely induce coughing.
Hematemesis has its own natural cessation period. However, if it involves Consumption (Deficiency Labor) and coughing, it will inevitably lead to death.
Regarding the blood of the Pericardium, it internally protects the Heart, externally connects to the vessels, and internally merges with the Liver. It merges with the Liver because both the Liver and the Pericardium belong to the Jueyin (Terminal Yin) category and share the same Qi nature. If there is excessive sexual activity or mental strain damaging the Shen (Spirit), blood from the Pericardium may be vomited. For those vomiting this type of blood, ten out of ten will die. Only if medications are not administered recklessly, and if there is heavy supplementation of the Heart and Kidney with substantial doses of Renshen (Ginseng Root), might one or two survive.
In cases where the body is not fatigued and there is no internal damage, sudden spitting of a few mouthfuls of blood, either purple or red, which comes out easily upon spitting, is blood from the Spleen collaterals. The Great Collateral of the Spleen connects throughout the body. If the collaterals do not harmonize with the main meridians, this type of bleeding occurs. Since it does not injure Yin below nor the meridians internally, it is the mildest and most superficial form of bleeding, which can heal without medication. If one fails to distinguish severity and treats it generally as hematemesis, causing cold coagulation in the collaterals and giving rise to other diseases, it is the fault of the physician.
Furthermore, the Five Zang Organs contain blood, while the Six Fu Organs do not. Vomiting blood from the Heart leads to death within one or two mouthfuls; vomiting blood from the Lungs presents as thread-like strands; vomiting blood from the Kidneys appears like red beans, leading to death within five to seven days. Vomiting blood from the Liver may result in survival or death, depending on whether the patient can self-nourish and whether the physician can treat skillfully. Blood from the Spleen involving the Luo-collaterals refers to the spitting of blood mentioned earlier.
Most cases of massive hematemesis involve blood from the Chong Sea. Physicians who lack clarity in classical theory mistakenly attribute it to blood from the Stomach. The Stomach, as the Official of Granaries, receives and holds food and water, and contains no blood itself. It is acceptable to say the blood exits through the Stomach, but incorrect to claim that blood resides within the Stomach.