Cheng Wuji: In miscellaneous diseases, hematemesis (vomiting blood) and hemoptysis (coughing up blood) are generally attributed to excess pathogens. However, in Shanghan (Cold Damage), hematemesis and hemoptysis are caused by erroneous use of sweating methods, purgative methods, and adverse effects of fire therapy. This is indeed not a mild case of cold transforming into heat, but rather a "Huai Bing" (complicated disease/sequelae). Treatment should follow the principle of regulating according to the pathogenic reversal.

Only in the case of Shaoyin disease with Jue (cold extremities) and exhaustion, where erroneous sweating forcibly disturbs the channel blood, is it stated as difficult to treat. For those who take Guizhi Tang (Cinnamon Twig Decoction) and vomit, they will subsequently vomit pus and blood (treat with Huangqin Tang or Mahuang Shengma Tang). If the pulse is floating and heat is severe, but moxibustion is applied instead, it will inevitably cause dry throat and spitting of blood (this is due to fire pathogen forcing blood upward; treat with Maohua Tang, Jiedu Tang, or Huangqin Shaoyao Tang).

In Shaoyin disease, if there is only Jue (cold extremities) without sweat, forced sweating will inevitably disturb the blood. Blood may flow from the mouth and nose or from the eyes. This is called "Xia Jue Shang Jie" (Jue at the lower part and exhaustion at the upper part) and is difficult to treat. In Shaoyin syndrome, if there is aversion to cold and fever but no headache, and erroneous heavy sweating causes blood to flow from the ears, eyes, mouth, and nose, it is named Yin blood loss with muteness. This differs from Yang blood conditions such as epistaxis (nosebleed).

In Shanghan disease, after seven or six days, if a severe purgative treatment was administered, resulting in a sunken and slow cun pulse, cold extremities, absent chi pulse at the lower part, dysphagia, spitting of pus and blood, and unceasing diarrhea, it is considered difficult to treat (treat with Mahuang Shengma Tang). If there is sore throat accompanied by hematemesis, and the face shows red patches like brocade patterns, it is classified as Yang Du (Yang Toxin), suitable for Shengma Biejia Tang.

Li Dongyuan: I treated a poor scholar suffering from Spleen and Stomach deficiency. After recovery from taking tonifying prescriptions, he lived in an empty room on a heated kang (heated brick bed), coughed, and vomited blood several times. I reasoned that this was due to long-term weakness, external cold invasion, internal heat accumulation, insufficiency of Qi ascending, and deficiency of Yang Qi on the exterior. The treatment should tonify the exterior Yang Qi and drain the interior deficient heat. Because he lived in an empty room in winter with thin clothing, his Yang was doubly depleted. Severe cold on the exterior obstructed the interior, preventing the fire pathogen from dispersing, thus causing blood to issue from the mouth. Recalling Zhang Zhongjing's treatment for Shanghan with floating-tight pulse: if Mahuang Tang (Ephedra Decoction) should have been used for sweating but was not, leading to epistaxis, administering Mahuang Tang then cured him immediately. This case is very similar. Therefore, I prescribed Mahuang Renshen Shaoyao Tang.

Mahuang Renshen Shaoyao Tang Formula:
Mahuang (1 qian, to dispel exterior cold), Guizhi (0.5 qian, to tonify exterior deficiency), Baishao Yao (1 qian), Huangqi (1 qian, to solidify the exterior and benefit Wei Qi), Zhi Gancao (1 qian, to tonify the Spleen), Wuweizi (5 grains, to calm Lung Qi), Maimendong (3 fen, to preserve Lung Qi), Renshen (3 fen, to benefit the insufficient Yuan Qi of the Sanjiao and solidify the exterior), Danggui (0.5 qian, to harmonize and nourish blood). All herbs are coarsely crushed. Take one dose, decoct with 3 bowls of water. First boil Mahuang until boiling, skim off the foam, reduce to 2 bowls. Add remaining herbs and decoct until 1 bowl remains. Strain and take hot. One dose before sleep leads to cure. Observing this formula, it serves as a model for all generations. It combines half of Zhang Zhongjing's Mahuang Tang with half of tonifying agents. Whenever deficient patients require formulas from Zhang Zhongjing, they should follow this principle.

Wang Haogu: In Shanghan, hematemesis occurs when various Yang channels are affected. Initially, heat is in the exterior, requiring sweating. If heat-toxin enters the channels and knots in the Five Zang Organs, forming internal stasis, hematemesis results. For severe blood stasis, use Didang Tang. For mild cases, use Tao Ren Chengqi Tang, combined with Xijiao Dihuang Tang and Sanhuang Wan.