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Dahuang (Rhei Radix et Rhizoma) inherits the harmonious qi of Earth and combines with the spring yang qi of Heaven; thus, its flavor is sweet and its nature is warm. Another view holds that it is slightly cold and non-toxic. Since the inherited qi is the same, its therapeutic indications are similar. It specializes in cooling blood and promoting blood circulation, nourishing essence by tonifying blood, and preserving blood. It is a crucial herb for treating epistaxis, hematemesis, and metrorrhagia caused by reckless bleeding.

Da Xiao Ji (Cirsii Herba), also known as Qianzhen Cao (Thousand-Needle Grass), has a sweet and warm flavor and nature. It nourishes essence and preserves blood, instantly eliminating hematemesis, epistaxis, sputum with blood, and hemoptysis, while stopping hematuria and metrorrhagia. Furthermore, it can break up blood stasis, reduce swelling, and detoxify bites from spiders and scorpions. It alleviates severe carbuncles and ulcers. When crushed and juiced to obtain half a bowl of liquid, mixed with child's urine or pure wine and drunk, it is effective. However, Xiao Ji (Cirsii Japonici Herba) has weaker efficacy; it only clears heat and cools blood, unlike Da Ji which can tonify and descend qi. Moreover, Xiao Ji only regulates blood diseases and does not treat surgical conditions. It should be avoided in patients with weak spleen and stomach, diarrhea, loss of appetite, and those with deficiency-cold of qi and blood.

Indications (referencing *Douzhen He Can*): Most suitable for stopping hematemesis, epistaxis, lower bleeding, and reckless menstrual bleeding during chickenpox/rubella in women.

Dahuang (Rhei Radix et Rhizoma) possesses a particularly strong yin qi of Earth and deep cold qi of Heaven; therefore, its flavor is extremely bitter, its nature is greatly cold, and it is non-toxic. It enters the Foot-Yangming, Foot-Taiyin, and Foot-Jueyin meridians, as well as the Hand-Yangming meridian. Its flavor and nature are both intense. The intense flavor promotes dispersing and entering the yin aspects, making its nature fierce and sharp in downward purgation. It also enters the blood aspect. For all forms of masses and accumulations, excess-heat dryness constipation, and tangible stagnations, it pushes out the old and generates the new, sweeping clean wherever it goes, possessing the merit of quelling chaos. It is strictly contraindicated for all intangible deficiency syndromes such as blood depletion with closure, and qi deficiency with closure.

To achieve rapid effects, Dahuang (Rhei Radix et Rhizoma) should be used raw; to achieve a milder effect, it should be cooked. It pushes out the old and generates the new, cleanses the intestines and stomach, eliminates blood stasis, rolls away stubborn phlegm, breaks up accumulations, stops pain, dissipates heat, resolves toxic carbuncles and swellings, eliminates retained fluids and old food retention, and clears phlegm-excess binding heat. Its nature moves directly without staying put, purging various excess-heat obstructions causing chest and abdominal fullness and dry fecal impaction. It is nicknamed "General" due to its fierce and swift action. However, if heat is in the blood aspect, the tangible pathogen can be purged; if heat is in the qi aspect, the intangible pathogen cannot be attacked, as this would damage the primordial qi instead.

Indications (referencing *Douzhen He Can*): Functions are the same as above. Used when acne/rash begins with abundant heat toxin, to purge various excess heats. Suitable for cases of large intestine dryness and constipation, inability to urinate, abdominal distension and irritability, especially in robust individuals with excessive blood heat and toxic accumulation. However, it severely damages the spleen and stomach and must not be used recklessly. To direct the action downward, use raw. For pathogens located in the upper jiao, use after soaking in wine.