（伤寒未全瘥因于交接而无病之人反得病也易者邪毒之气交相易换也男子病
新瘥妇人与之交而得病名曰阳易妇人病新瘥男子与之交而得病名曰阴易其候身重气乏百节解散头
重不举目中生花热上中胸火浮头面憎寒壮热在男子则阴肿小腹绞痛在妇人则里急连腰胯内痛
甚者手足冷挛蜷男子卵陷入腹妇人痛引阴中皆难治也若吐舌出数寸者必死）
易病阳症。（烧 散竹皮汤）阴症。（ 鼠屎汤当归白术汤）大便不通。昏乱惊惕（妙香丸）
按阴阳易病。得离经脉者死。太过而一呼三至曰至。不及而一呼一至曰损。此离于经常
之脉也。惟易病有之。
（瘥后犯房事而热名房劳复其候头重眼花腰背痛小腹里急心胸烦闷）
房劳。头重。目花。小腹绞痛。（赤衣散烧 散竹皮汤选用）虚弱脉微。（四君子汤送烧 散）
（大病新瘥最忌思虑伤神多言耗气梳浴行动太早则因劳发热复病如初）
劳复发热。（小柴胡主之脉浮汗解脉沉下解）劳神。（归脾汤）气弱脉细。（补中益气汤）一
切劳复。（鳖甲为末炒黄米汤送下）
（凡病瘥后先进清粥汤次进浓粥汤次进糜粥亦须少少与之切勿令任意过食也至于
酒肉尤当禁忌若有不谨便复发热名为食复）
食复轻者。（香砂枳术汤）重者。（枳实栀子豉汤）酒复。（小柴胡加葛根黄连）
（伤寒病尚未完全痊愈时，因进行房事，导致原本无病的一方反而患病。所谓“易”，是指邪毒之气相互交换。男子病初愈，与女子行房而致病，称为“阳易”；女子病初愈，与男子行房而致病，称为“阴易”。其症状表现为身体沉重、气力匮乏、全身关节松弛无力、头部沉重难以抬起、眼前发黑或见花、热气上冲至胸中、面部浮热、怕冷且高热。在男子则出现阴茎肿胀、小腹绞痛；在女子则出现腹部拘急疼痛并牵连腰胯内部疼痛。病情严重者，手足冰冷、抽搐蜷缩，男子睾丸缩入腹中，女子疼痛牵引至阴部，这些都属于难治之症。如果患者吐出舌头的长度达数寸，则必定死亡。）
对于易病中的阳证，使用烧裈散和竹皮汤；对于阴证，使用鼠矢汤、当归汤和白术汤。若出现大便不通、神志昏乱、惊恐不安的症状，使用妙香丸。
按语：阴阳易病，如果出现离经脉者，预后不良必死无疑。“太过”指一呼之间脉搏跳动三次，称为“至脉”；“不及”指一呼之间脉搏仅跳动一次，称为“损脉”。这是偏离正常常规的脉象，只有易病才会出现这种脉象。
（病愈后犯房事而导致发热，称为“房劳复”。其症状表现为头部沉重、眼花、腰背疼痛、小腹拘急、心胸烦闷。）
针对房劳复引起的头重、眼花、小腹绞痛，选用赤衣散或烧裈散、竹皮汤。若体质虚弱、脉象微弱，用四君子汤送服烧裈散。
（大病刚刚痊愈，最忌讳思虑过度损伤心神，多说话耗伤元气，过早梳洗沐浴或行动，则会因为劳累而发热，疾病复发如初。）
因劳累导致的发热，以小柴胡汤为主治：脉浮者通过发汗解表，脉沉者通过泻下通便来解除病邪。因劳神所致者，使用归脾汤。因气弱、脉细所致者，使用补中益气汤。所有类型的劳复，可将鳖甲研为末，炒黄后用黄米汤送服。
（凡是病愈之后，应先喝清淡的米汤，再喝浓稠的米汤，最后喝稀粥，并且必须少量多次给予，切勿让患者任意过量饮食。至于酒肉，尤其应当禁忌。如果有不谨慎而过食的情况，便会再次发热，这称为“食复”。）
(When a Taiyang disease (disease of the Taiyang channel) has not yet fully resolved, sexual intercourse may cause the previously healthy partner to fall ill. The term "Yi" (Exchange) refers to the mutual exchange of pathogenic toxic qi. If a man recovers from an illness and engages in intercourse with a woman, resulting in her illness, it is called "Yang Yi" (Yang Exchange); if a woman recovers and engages in intercourse with a man, resulting in his illness, it is called "Yin Yi" (Yin Exchange). The symptoms include heaviness of the body, lack of energy, relaxation of all joints, heaviness of the head making it difficult to lift, visual disturbances such as seeing spots or darkness, heat rushing up to the chest, floating heat on the face, aversion to cold accompanied by high fever. In men, this manifests as swelling of the penis and colicky pain in the lower abdomen; in women, it presents as abdominal urgency and pain radiating to the waist and hips. In severe cases, there is coldness and convulsive curling of the hands and feet, retraction of the testes into the abdomen in men, and pain radiating to the vagina in women; these are all difficult to treat. If the tongue protrudes several inches, death is certain.)
For Yang-pattern Yi disease, use Shaokun San (Scraped Underwear Powder) and Zhupi Tang (Bamboo Peel Decoction). For Yin-pattern Yi disease, use Shushi Tang (Mouse Feces Decoction), Danggui Tang (Angelica Sinensis Decoction), and Baizhu Tang (Atractylodes Macrocephala Decoction). For symptoms of constipation, mental confusion, and fright, use Miaoxiang Wan (Wonderful Fragrance Pill).
Note: In Yin-Yang Yi disease, the appearance of Li Mai (Departing Pulse) indicates a fatal prognosis. "Excess" refers to three pulse beats per exhalation, known as Zhi Mai (Arriving Pulse); "Deficiency" refers to one pulse beat per exhalation, known as Sun Mai (Damaged Pulse). These are pulses deviating from the normal rhythm, found only in Yi disease.
(Fever occurring after recovery due to sexual activity is called Fanglao Fu (Relapse due to Sexual Exhaustion). Symptoms include heavy head, blurred vision, backache, abdominal urgency, and mental restlessness.)
For heavy head, blurred vision, and colicky lower abdominal pain caused by Fanglao, select Chiyi San (Red Garment Powder) or Shaokun San and Zhupi Tang. For weakness and faint pulse, administer Sijunzi Tang (Four Gentlemen Decoction) to deliver Shaokun San.
(Immediately after recovering from a major illness, excessive thinking that damages Shen (Spirit), excessive talking that consumes Qi, and early bathing or physical activity should be strictly avoided, as they can cause fever due to labor and lead to relapse similar to the original illness.)
For fever due to labor, Xiaochaihu Tang (Minor Bupleurum Decoction) is the primary formula: if the pulse is floating, resolve via sweating; if sinking, resolve via purgation. For relapse due to mental exertion, use Guipi Tang (Spleen-Restoring Decoction). For weak Qi and fine pulse, use Buzhong Yiqi Tang (Middle-Warmer-Boosting Qi-Supplementing Decoction). For all types of Laofu (Labor Relapse), take powdered Biejia (Turtle Shell), stir-fried until yellow, and swallow with Huangmi Tang (Yellow Millet Decoction).
(After any illness resolves, one should first consume clear rice soup, then thick rice soup, and finally congee, giving small amounts frequently. One must never allow arbitrary overeating. Alcohol and meat are particularly contraindicated. If dietary caution is neglected and fever recurs, it is called Shipu (Food Relapse).)
For mild Shipu, use Xiangsha Zhizhu Tang (Aucklandia and Amomum Atractylodes Formula); for severe cases, use Zhishi Zhizi Chi Tang (Immature Bitter Orange, Gardenia, and Fermented Soybean Decoction). For relapse due to alcohol consumption, use Xiaochaihu Tang modified with Gegen (Kudzu Root) and Huanglian (Coptis Rhizome).