After the recovery from Shanghan (Cold Damage disease), the condition known as Yin-Yang Yi (Yin-Yang Exchange) presents with a heavy body, shortness of breath, urgency and tension in the lower abdomen, sometimes drawing into spasms of the genitalia, heat rushing up to the chest, heaviness of the head making it difficult to lift, blurred vision or seeing spots before the eyes, and stiffness and cramping of the knees and calves. This is primarily treated with Shao Kun San (Burning Undergarment Powder).

Shao Kun San
Take the fabric of a woman's undergarment (close-fitting underwear) near the genital area, cut it off, burn it to ash, mix with water, and administer one Fang Cun Bi (a square-inch measure) per dose. Take three times daily. When urination becomes smooth and the glans penis swells slightly, the patient will recover. If the patient is a woman, take the crotch part of a man's undergarment, burn it to ash, and administer.

I once treated a patient who had contracted Shanghan but relapsed due to sexual intercourse before full recovery, facing imminent death. I used Du Shen Tang (Single Ginseng Decoction) to deliver Shao Kun San. In cases where patients consumed over one jin (approx. 500g) of Ginseng and recovered, there were three or four such instances. This confirms that medical treatment should not be rigid.

Appendix:
Treating Shanghan after recent recovery where Yin and Yang Qi are not yet harmonized, leading to illness due to sexual intercourse. In men, this causes swelling of the scrotum and severe colic pain radiating into the abdomen; in women, it causes urgency in the lower abdomen and pain extending from the waist and hips into the internal abdomen. This is named "Yin-Yang Yi". If a man recovers from illness but has not fully stabilized and engages in intercourse with a woman, contracting the disease, it is called "Yang Yi"; if a woman recovers but has not fully stabilized and engages in intercourse with a man, contracting the disease, it is called "Yin Yi". It does not occur between two men or two women. It is called "Exchange" because Yin and Yang mutually affect each other, and the pathogenic toxin attaches to the person like an exchange. The symptoms include fever, heat rushing to the chest, heavy head unable to be lifted, blurred vision, stiff and cramped limbs, severe lower abdominal colic, and curled hands and feet, which indicates a fatal prognosis. Some do not die immediately but suffer from lower abdominal urgency, heat rushing to the chest, heavy head, inability to lift the head, joint separation, weak meridians, deficiency of blood and Qi, exhaustion of bone marrow, mental confusion, weak breathing, decreasing strength, inability to move or rise from bed, requiring support from others, lasting for months or years until death. Suitable formulas include Shao Kun San, Shu Fen Tang (Mouse Feces Decoction), Zhu Ru Tang (Bamboo Shavings Decoction), Qing Zhu Ru Tang (Green Bamboo Shavings Decoction), Gan Jiang Tang (Dried Ginger Decoction), and Dang Gui Bai Zhu Tang (Angelica and Atractylodes Macrocephala Decoction). (Haizang stated: For heat patterns, use Shao Kun San and Zhu Pi Tang; for cold patterns, use Shu Fen Tang and Dang Gui Bai Zhu Tang. Regarding the correction of Miao Xiang Wan treating miscellaneous diseases of Yin-Yang Yi containing realgar, borneol, musk, etc., these treat heat patterns.)

Qing Zhu Ru Tang
For women whose illness has not stabilized, causing heat to rush to the chest due to movement, resulting in stiff and cramped hands and feet, twitching resembling wind-stroke. This formula is suitable.

Gua Lou Tang (Gua Lou [Trichosanthes Fruit] 1 liang) Qing Zhu Ru (Scrape half sheng, preferably from light bamboo). Boil the above in 2 sheng of water to obtain 1.2 sheng. Remove dregs and divide into two or three doses.

Miao Xiang Wan
Treats Yin-Yang Yi where the disease persists, accompanied by constipation, confused spirit, restlessness, and fear.

Chen Sha (Cinnabar, separately ground fine and washed with water, 3 qian) Bing Nao (Borneol) Ni Fen (Calomel) She Xiang (Musk) Niu Huang (Calculus Bovis, each 7.5 qian) Jin Bo (Gold Leaf, 5 pieces) Ba Dou Shuang (Croton Seed Frost, 2.5 qian). Grind all into fine powder. Add Huang La (Yellow Beeswax, 3 qian) and Mi (Honey, 1 small spoon), refine evenly, and mix with medicine to form pills. Each 1 liang of medicine makes 30 pills. Administer 5 pills with rice drink; 3 pills for the weak; 7 pills for the strong may also be used. Stop when bowel movements become unobstructed.

Bai Yi Zhi
Treats relapse due to sexual intercourse, with swollen or retracted testicles, severe abdominal colic, or fecal impaction. Extract juice from several earthworms and administer orally; it is effective.

Haizang
If Yin-Yang Yi indeed presents with Yin pulse, use Dang Gui Si Ni Tang (Angelica Cinnamon Twig Decoction) to deliver Shao Kun San according to the syndrome. If the pulse is at Shao Yin, use Tong Mai Si Ni Tang (Pulse-Reviving Cinnamon Twig Decoction) to deliver Shao Kun San. If the pulse is at Tai Yin, use Si Shun Li Zhong Wan (Four-Obedient Spleen-Harmonizing Pill) to deliver Shao Kun San. Using medicines corresponding to their respective meridians ensures rapid efficacy.

Shu Fen Tang
Treats Yin Yi in men after Shanghan.

Jiu Bai Gen (Leek White Root, 1 handful) Shu Fen (Mouse Feces, 14 grains, those pointed at both ends are authentic). Boil these two ingredients in 5 sheng of water to obtain half a sheng. Remove dregs, boil again for three boils, and take warm. If effective but no sweat, take again. This also treats various types of Lao Fu (Relapse due to exertion).

Dang Gui Bai Zhu Tang
Treats women whose illness has not stabilized, causing lower abdominal urgent pain, inability to move waist, hips, and limbs due to weakness, and fever due to movement.

Bai Zhu (Atractylodes Macrocephala Rhizome) Dang Gui (Angelica Sinensis Radix) Gui Zhi (Cinnamon Twig) Fu Zi (Prepared Aconite Lateral Root, raw) Gan Cao (Licorice Root) Shao Yao (Peony Root) Huang Qi (Astragalus Membranaceus Root) Ren Shen (Ginseng Radix et Rhizoma) (each 2.5 qian) Sheng Jiang (Fresh Ginger, half liang). Chop coarsely, decoct in water, and take. After eating, take again. Cover warmly to induce slight sweating; the disease will resolve.

Li Liangzuo's son suffered from Taiyang syndrome with floating and rapid pulses at both cun and chi positions, weak upon pressure. I observed internal Yin deficiency and cured him with Shen Shu Jia Gan Jiang Tang (Divine Efficacy Atractylodes Decoction plus Dried Ginger). Later he fell ill again. I observed his unwillingness to speak and drooping head, suspecting sexual excess. Upon inquiry, he admitted to it. I administered Da Jian Zhong Tang (Great Construct Middle Decoction) three or four times. External Yang retreated inward, pulse returned to deep and small, revealing Yin signs. Then I administered pills containing Gan Jiang, Shao Yao, and Hui Xiang for five or six doses. Within three days, he took about 600-700 pills, and the pulse revived. I then used Da Jian Zhong Tang again, leading to profuse sweating and resolution.

Shan Shi
For Yin syndrome Shanghan caused by sexual indulgence, stir-fry Chen Pi (Citrus Reticulata Pericarpium) in a hot pan until charred, cook with wine, filter, and drink the wine.

Jiu Gen San
Treats Yin-Yang Yi after Shanghan, characterized by heavy head, pain in all joints, weak breathing, inability to rise from bed, severe cases with curled hands and feet, swollen and painful testicles.

Jiu Gen (Leek Root) Gua Lou Gen (Trichosanthes Radix) (each 2 liang) Qing Zhu Ru (Green Bamboo Shavings) Gan Jiang (Dried Ginger, processed, each half liang). Finely chop and mix evenly. Divide into eight doses. Each dose uses one large cup of water, boiled down to half a cup. Remove dregs, add one zi (measure) of powdered mouse feces, stir well, and take at any time. Sheng Ji Fang: Sieve 5 qian bi, boil in 1.5 cups of water to 1 cup. Remove dregs and take warm before meals. Also named Feng Ben Tang.

Gan Jiang San
Treats women suffering from Shanghan. Even if recovered, intercourse within 100 days must be avoided, otherwise Yin-Yang Yi will occur, inevitably causing body stiffness, curled hands and feet, and near-death sensation. In men, it is called Yin Yi; in women, Yang Yi. Prompt sweating can cure it. If four days have passed, it is incurable. Patients should take this medicine. Symptoms include heavy body, lower abdominal urgency, heat rushing to chest, heavy head unable to lift, blurred vision, and knee/calf stiffness. Use Gan Jiang (4 liang, powdered), mix with boiling water, and take continuously. Cover with blankets to induce sweating for relief. Hands and feet extend, and the patient recovers.

Er Hui San
Treats Shanghan Yin-Yang Yi.

Hand and foot fingernails/toenails (20 pieces: use female's nails for male patient, male's for female patient) Zhong Yi Dang (Crotch of undergarment, one piece near genitals: use female's for male patient, male's for female patient). Burn all to ash, grind finely, divide into three doses. Take at any time with warm wine or rice soup.

Yi Lin Yue
The appearance of Li Jing Mai (Departing Pulse) mostly indicates death. Excessive pulse is called "Zhi", three beats per exhalation is "Zhi". Insufficient pulse is called "Sun", one beat per exhalation is "Sun". Only Yin-Yang Yi disease presents with these pulses.

Zhang Jingyue
Suppose a woman has just recovered from illness and is not yet stable, and a man engages in intercourse with her. If she suddenly falls ill due to external pathogenic factors, this is actually not transmission of residual pathogens. Doctors seeing the rapid onset call it Yin Yi. How to distinguish this legally? Patients with Yi disease present with the symptoms described in the previous article. Is this comparable to external contraction? If it were external Wind-Cold, there should be exterior signs. How could there be lower abdominal urgency drawing into genital spasms? Or someone might say: Suppose a man recovers but is not stable, forces intercourse, and falls ill himself. He still has lower abdominal urgency and genital spasms, identical to Yi disease. Investigating the principle, why does he not infect others but relapse himself? Examining the syndrome and treatment, what method applies? Although self-relapse is similar to Yi disease, Shao Kun San is also used to soothe and calm the Qi. The so-called Yi disease involves moving residual pathogens through intercourse, and since the person's healthy Qi is originally deficient, they can be infected. Otherwise, how could they receive the pathogen? Now, self-relapse occurs because healthy Qi is still deficient, and residual pathogens are activated by movement, entirely distinct from external contraction. Thus, it is similar to Yi disease, and Shao Kun San is also used to stabilize healthy Qi. Once healthy Qi is stabilized, residual pathogens naturally subside.