Heat entering the blood chamber refers to the Chong Mai (Penetrating Vessel), which is the sea of blood, also known as the blood chamber. Both men and women possess this blood qi and the Chong Mai. When affected by heat pathogen, blood will flow recklessly; in men, it manifests as lower bleeding and delirious speech, because the evil heat has transmitted into the Yangming Fu organ; in women, it manifests as alternating chills and fever resembling malaria, where the pathogen enters along the meridians. Both cases are termed "heat entering the blood chamber." If Taiyang disease does not resolve, and heat binds in the Bladder, with the patient appearing manic-like and bleeding spontaneously, they will recover; if not, Guizhi Tang (Cinnamon Twig Decoction) is used. In Yangming disease, lower bleeding and delirium accompanied by chest fullness resembling Jie Xiong (chest binding syndrome), and seeing ghosts at night, indicate heat entering the blood chamber, treated with Xiaochaihu Tang (Minor Bupleurum Decoction). Lower jiao blood stasis presents with a manic-like state, urgency and binding pain in the lower abdomen, free urination, black stools, or diarrhea without exterior or interior signs, persistent rapid pulse, rapid digestion with easy hunger, and constipation for many days; this is blood stasis, treated with Tao Ren Cheng Qi Tang (Peach Kernel Cathartic Decoction). Shaoyin disease presenting with bloody purulence in stool, or abdominal fullness with discharge resembling fish brains, is primarily treated with Taohua Tang (Peach Flower Decoction).

Si Ni (Four Extremities Cold) refers to cold and unwarmed hands and feet. When the pathogen is in the exterior, hands and feet are hot. When the pathogen is in half-exterior and half-interior, hands and feet are warm. However, when the pathogen transmits to Shaoyin, hands and feet become cold and reversed. Progression from heat to warmth, then from warmth to cold reversal, indicates a pathogen transmitting through the meridians; mild cases are treated with Si Ni San (Four Reversal Powder), while severe cases are purged with Cheng Qi Tang (Cathartic Decoction). If cold reversal occurs immediately upon onset of illness, mild cases are treated with Lizhong Tang (Regulate the Middle Decoction), and severe cases with Si Ni Tang (Four Reversal Decoction) to warm. This is due to pathogen affecting the Yin meridians, representing insufficient Yang and excess Yin. Symptoms such as aversion to cold with cold reversal, curling up in bed, irritability, vomiting, diarrhea, and absent pulse are all ominous prognoses.

Constipation arises from excessive sweating or diuresis, which depletes body fluids, leading to dryness of the intestines and stomach. Generally, when heat pathogen transmits to the Yangming Fu organ, there are many interior syndromes. If thirst, delirium, solid pulse, mania, tidal fever, spontaneous sweating, dark urine, or abdominal distension, fullness, hardness, and pain are observed, urgently use one of the three Cheng Qi Tangs (Cathartic Decoctions) to purge; once stool passes, the heat resolves. If the pulse is floating, indicating residual exterior signs, or accompanied by vomiting, it suggests the pathogen has not fully entered the Fu organs but remains in the half-exterior/half-interior region; Xiaochaihu Tang (Minor Bupleurum Decoction) should be used to harmonize. When stool becomes hard and dry, necessitating purgation, Da Chaihu Tang (Major Bupleurum Decoction) is used. If Yangming disease involves profuse sweating, or if sweating and diuresis have already occurred yet constipation persists, this indicates exhaustion of body fluids; honey suppositories (Mi Dao) should be used to moisten and unblock.