（《素问·阴阳类论》）
雷公曰∶请问短期。黄帝曰∶冬三月之病，病合于阳者，至春正月，脉有死征，皆归出春。（冬三月者，阴盛时也。
病合于阳者，阳证阳脉也。出春，春尽夏初也。以水王之时而病合于阳者，时气不足，病气有余也。及至孟春正月，阳
气发生，则阳邪愈胜，阴气愈竭。若脉有死征，则出春交夏而阳盛阴衰俱已至极，无所逃矣。）冬三月之病，在理已尽，
草与柳叶皆杀，（在理已尽，谓察其脉证之理，已无生意也。以冬月之病而得此，则凡草色之青，柳叶之见，阴阳气易，
皆其死期，故云皆杀也。杀，少戒切。）春阴阳皆绝，期在孟春。（阴阳皆绝，谓阴中无阳，阳中无阴，彼此相绝，不交
通也。病由冬月而春犹若此，是生气之竭也，短期当在孟春矣。）
春三月之病曰阳杀，（春月阳气方升，而病在阳者，故曰阳杀。杀者，衰也。）阴阳皆绝，期在草干。（以三春阳杀之
病，而阴阳痞绝者，期在深秋草干之时，金气胜而病发于春者死矣。）
夏三月之病，至阴不过十日，（脾肾皆为至阴，夏三月以阳盛之时而脾肾伤极，则真阴败绝，天干易气不能堪矣，故
不过十日也。）阴阳交，期在 水。（阴阳交者，阴脉见于阳，则阳气失守，阳脉见于阴，则阴气失守。若是者，虽无危
证而脉象已逆，见于夏月，则危于仲秋 水之时也。 音敛，清也。）
秋三月之病，三阳俱起，不治自已，（秋时阳气渐衰，阴气渐长，虽三阳脉病俱起，而阳不胜阴，故自已也。）阴阳
交合者，立不能坐，坐不能起，（秋气将敛未敛，故有阴阳交合为病者，则或精或气必有所伤，而致动止不利。盖阳胜阴，
故立不能坐；阴胜阳，故坐不能起。）三阳独至，期在石水，（三阳独至即三阳并至，阳亢阴竭之候也。阴竭在冬，本无
生意，而孤阳遇水，终为扑灭，故期在冰坚如石之时也。）二阴独至，期在盛水。（二阴全元起本作三阴。即所谓三阴并
至，有阴无阳也。盛水者，正月雨水之候。孤阴难以独立，故遇阳胜之时，则不能保其存也。）
(Su Wen · Yin Yang Lei Lun)
Leigong asked: May I ask what is meant by "short-term" (the period indicating the time of death in a disease)? Huangdi replied: For diseases occurring during the three months of winter, if the pathology aligns with Yang (manifesting as Yang syndromes such as fever or flushed face), and by the first month of spring, the pulse shows signs of death, the patient will generally die at the transition from late spring to early summer. ("The three months of winter" refers to the time when Yin energy is at its peak. "Pathology aligning with Yang" means the presence of Yang syndrome pulses and symptoms. "Exiting spring" refers to the period from late spring to early summer. When Yang pathology occurs during the season governed by Water (winter), it indicates that the seasonal Yin Qi is insufficient to control the excess pathogenic Qi. By the beginning of spring (Mengchun), when Yang Qi begins to arise, the Yang pathogen becomes even more dominant, while the body's Yin Qi becomes increasingly depleted. If the pulse exhibits signs of death, then at the transition from spring to summer, the state of extreme Yang excess and Yin deficiency reaches its zenith, leaving no room for recovery.) Conversely, for diseases occurring during the three months of winter, if upon medical analysis there is no hope for life left, ("No hope for life left" means that through observation of the pulse and symptoms, it is determined that there is no vitality remaining. Since this condition arises from a winter disease, whenever grass turns green and willow leaves sprout—times when Yin and Yang energies shift—these are the times of death; hence it is said "all perish." Perish, pronounced shài, signifies肃杀 (severe killing/ending).) If, in spring, Yin and Yang energies are completely severed, the time of death will be in Mengchun (the first month of spring). ("Yin and Yang completely severed" means there is no Yang within Yin, and no Yin within Yang; they are separated and do not interact. If the disease persists from winter into spring in this manner, it indicates the exhaustion of Sheng Qi (vital generating energy), and the time of death should be in Mengchun.)
Diseases occurring during the three months of spring are called "Yang Sha" (Yang decline/perishing). (In spring, Yang Qi is just rising; if the pathology is in the Yang aspect, it is termed Yang Sha. Sha means decline or perishing.) If Yin and Yang are completely severed at this time, the time of death will be when grass dries up (late autumn). (For diseases in the spring when Yang Qi rises, if Yin and Yang are blocked and severed, the time of death will be in late autumn when grass dries, because Metal Qi (Autumn Qi) prevails, and those whose illness originated in spring will die when Autumn arrives.)
For diseases occurring during the three months of summer, if the Zhi Yin (Spleen and Kidney) are affected, death will occur within ten days. (Spleen and Kidney both belong to Zhi Yin. Summer is a time of extreme Yang; if Spleen and Kidney are severely damaged, leading to the collapse of True Yin, which cannot withstand the changing heavenly stems and earthly branches, death will occur within ten days.) If there is an interaction between Yin and Yang (Yin-Yang Jiao), the time of death will be during the Water season (Winter). ("Yin-Yang Jiao" refers to Yin pulses appearing in Yang positions, causing Yang Qi to lose its hold, or Yang pulses appearing in Yin positions, causing Yin Qi to lose its hold. In such cases, even without critical symptoms, the pulse is already inverted. Appearing in summer, this becomes critical during the Water-dominant period following mid-autumn. Lian, pronounced liǎn, means cold/clear/converging.)
For diseases occurring during the three months of autumn, if the pulses of the Three Yang meridians rise simultaneously, the disease may resolve spontaneously without treatment. (In autumn, Yang Qi gradually declines and Yin Qi gradually grows. Even if the pulses of the Three Yang meridians appear simultaneously, since Yang cannot overcome Yin, the disease will resolve on its own.) If the pathology involves the interaction of Yin and Yang, resulting in the inability to sit while standing, or unable to stand while sitting, (As autumn weather is converging but not yet fully converged, diseases caused by Yin-Yang interaction will inevitably damage Jing (Essence) or Qi, leading to motor impairment. Generally, if Yang overcomes Yin, one cannot sit while standing; if Yin overcomes Yang, one cannot stand while sitting.) If only the Three Yang meridians are excessively active, the time of death will be during the "Stone Water" period (when ice is hard as stone, i.e., deep winter). ("Three Yang Du Zhi" means the convergence of all Three Yang meridians, a sign of Yang hyperactivity and Yin exhaustion. Yin exhaustion in winter implies no vitality; solitary Yang encountering Water (Winter Cold) will ultimately be extinguished, so the time of death is in deep winter.) If only the Two Yin meridians are excessively active, the time of death will be during the "Sheng Water" period (the rainy season of the first lunar month). (Two Yin, according to Quan Yuanqi's edition, is written as Three Yin. This refers to the convergence of all Three Yin meridians, having Yin without Yang. Sheng Water refers to the climate of rain in the first month. Solitary Yin cannot exist independently; thus, when encountering prevailing Yang, it cannot sustain life.)