二十四难曰∶手足三阴三阳，气已绝，何以为候？何知其吉凶不？然∶足少阴气绝，即骨枯。
少阴者，冬脉也，伏行而温于骨髓。故骨髓不温，即肉不着骨；骨肉不相亲，即肉濡而却；肉濡而
却，故齿长而枯，发无润泽；无润泽者，骨先死。戊日笃，己日死。
足太阴气绝，则脉不营其口唇。口唇者，肌肉之本也。脉不营，则肌肉不滑泽；肌肉不滑泽，
则肉满；肉满则唇反，唇反则肉先死。甲日笃，乙日死。
足厥阴气绝，即筋缩引卵与舌卷。厥阴者、肝脉也。肝者、筋之合也。筋者、聚于阴器而络于舌本。
故脉不营，则筋缩急；筋缩急即引卵与舌；故舌卷卵缩，此筋先死。庚日笃、辛日死。
手太阴气绝，即皮毛焦。太阴者、肺也，行气温于皮毛者也。气弗营，则皮毛焦；皮毛焦，
则津液去；津液去，即皮节伤；皮节伤，则皮枯毛折；毛折者、则毛先死。丙日笃、丁日死。
手少阴气绝，则脉不通；脉不通，则血不流；血不流，则色泽去。故面色黑如黧，此血先死。
壬日笃，癸日死。
三阴气俱绝者，则目眩转，目瞑；目瞑者，为失志；失志者，则志先死，死即目瞑也。
六阳气俱绝者，则阴与阳相离。阴阳相离，则腠理泄，绝汗乃出，大如贯珠，转出不流，即气先死。
旦占夕死，夕占旦死。
第二十四难说：手足三阴经和三阳经的气血如果断绝，会有什么征候？如何判断其吉凶预后呢？回答说：足少阴经的气血断绝，就会出现骨骼枯槁的现象。
少阴经是冬季的脉象，潜行于体内而温煦骨髓。所以骨髓得不到温煦，肌肉就无法附着在骨骼上；肌肉与骨骼不相依附，肌肉就会松弛萎缩并退缩；肌肉松弛退缩，所以牙齿显得变长且干枯，头发失去润泽；头发没有润泽，说明骨气先已死亡。戊日病情加重，己日死亡。
足太阴经的气血断绝，则经脉不能濡养口唇。口唇是肌肉的根本所在。经脉不能濡养，肌肉就不滑润光泽；肌肉不滑润光泽，肌肉就会肿胀满实；肌肉肿胀满实则导致口唇外翻，口唇外翻说明肌肉之气先已死亡。甲日病情加重，乙日死亡。
足厥阴经的气血断绝，就会出现筋脉拘挛，牵引睾丸和舌头卷缩。厥阴经是肝的经脉。肝主筋，是筋的汇聚之处。筋脉聚生于生殖器部位并联络于舌根。所以经脉气血不能濡养，筋脉就会拘急收缩；筋脉拘急收缩就会牵引睾丸和舌头；因此出现舌头卷缩、睾丸上提，这是筋气先已死亡。庚日病情加重，辛日死亡。
手太阴经的气血断绝，就会出现皮毛焦枯。手太阴经属于肺，肺运行卫气以温煦皮毛。卫气不能濡养，皮毛就会焦枯；皮毛焦枯，津液就会耗散；津液耗散，皮肤关节就会受损；皮肤关节受损，皮肤就会干枯、毛发折断；毛发折断，说明毛气（肺气）先已死亡。丙日病情加重，丁日死亡。
手少阴经的气血断绝，则血脉不通畅；血脉不通畅，血液就不能流动；血液不流动，面色就会失去光泽。所以面色黑得像黑炭一样，这是血气先已死亡。壬日病情加重，癸日死亡。
三阴经的气血全部断绝，就会出现头晕眼花、视物旋转、眼睛闭合；眼睛闭合，是因为神志丧失；神志丧失，说明志气先已死亡，死亡时表现为眼睛闭合。
六阳经的气血全部断绝，则阴气与阳气相互分离。阴阳相互分离，腠理就会开泄，绝汗随之流出，汗珠大如串珠，转动而不流下，这是阳气先已死亡。早晨占测到症状，傍晚就会死亡；傍晚占测到症状，第二天早晨就会死亡。
Difficulty 24 states: When the Qi of the three Yin and three Yang meridians of the hands and feet is exhausted, what are the signs? How can one determine their auspiciousness or inauspiciousness (prognosis)? The answer is: When the Qi of the Foot Shaoyin Meridian (Kidney Meridian of Foot-Shaoyin) is exhausted, the bones become withered.
The Shaoyin Meridian corresponds to the winter pulse; it runs deep within and warms the bone marrow. Therefore, if the bone marrow is not warmed, the flesh cannot adhere to the bones; if the flesh and bones are not closely attached, the flesh becomes flaccid and retracts; due to this flaccidity and retraction, the teeth appear elongated and withered, and the hair loses its luster; the lack of luster indicates that the Qi of the bones has died first. The condition will worsen on Wu days and death will occur on Ji days.
When the Qi of the Foot Taiyin Meridian (Spleen Meridian of Foot-Taiyin) is exhausted, the vessels fail to nourish the lips. The lips are the root of the muscles. If the vessels do not nourish them, the muscles lose their smoothness and luster; if the muscles are not smooth and lustrous, they become swollen and full; when swollen and full, the lips evert; lip eversion indicates that the Qi of the flesh has died first. The condition will worsen on Jia days and death will occur on Yi days.
When the Qi of the Foot Jueyin Meridian (Liver Meridian of Foot-Jueyin) is exhausted, there is tendon contraction pulling on the genitals and tongue rolling. The Jueyin Meridian is the Liver Meridian. The Liver governs the tendons, which converge at the genitalia and connect to the base of the tongue. Therefore, if the vessels fail to nourish them, the tendons contract and tighten; tight tendons pull on the genitals and tongue; thus, tongue rolling and testicular retraction occur, indicating that the Qi of the tendons has died first. The condition will worsen on Geng days and death will occur on Xin days.
When the Qi of the Hand Taiyin Meridian (Lung Meridian of Hand-Taiyin) is exhausted, the skin and hair become scorched and withered. The Hand Taiyin belongs to the Lung, which circulates Wei Qi (Defensive Qi) to warm the skin and hair. If Wei Qi fails to nourish, the skin and hair become withered; if the skin and hair are withered, body fluids are lost; if body fluids are lost, the skin and joints are damaged; if the skin and joints are damaged, the skin becomes dry and hair breaks; broken hair indicates that the Qi of the hair (Lung Qi) has died first. The condition will worsen on Bing days and death will occur on Ding days.
When the Qi of the Hand Shaoyin Meridian (Heart Meridian of Hand-Shaoyin) is exhausted, the vessels become obstructed; if the vessels are obstructed, blood does not flow; if blood does not flow, the complexion loses its luster. Therefore, the facial color becomes black like charcoal, indicating that the Qi of blood has died first. The condition will worsen on Ren days and death will occur on Gui days.
When the Qi of all three Yin meridians is exhausted, dizziness, vertigo, and eye closure occur. Eye closure signifies the loss of Zhi (Will/Spirit); loss of Zhi indicates that the Will has died first, manifesting as eye closure upon death.
When the Qi of all six Yang meridians is exhausted, Yin and Yang separate from each other. When Yin and Yang separate, the interstices (Cou Li) become permeable, and absolute sweat (Jue Han) flows out. The sweat beads are large like strings of pearls, rotating but not flowing down, indicating that Yang Qi has died first. If symptoms are observed in the morning, death occurs in the evening; if observed in the evening, death occurs the next morning.