四十八难曰∶人有三虚三实，何谓也？
然∶有脉之虚实，有病之虚实，有诊之虚实也。脉之虚
实者，濡者为虚，紧牢者为实。病之虚实者，出者为虚，入者为实∶言者为虚，不言者为实；缓者
为虚，急者为实。诊之虚实者，濡者为虚，牢者为实；痒者为虚，痛者为实。外痛内快，为外实内
虚；内痛外快，为内实外虚。故曰虚实也。
虚者，空虚，正气不足也。实者，强实，邪气有余也。以脉言之，濡者软细，故为虚也。紧
牢者，紧弦劲，牢沉劲，故为实也。然脉之虚实，不仅乎此，举此可类推也。以病言之，出者为虚，
是五脏自病，由内而之外，所谓内伤是也。入者为实，是五邪所中，由外而之内，所谓外感是也。
然出者间亦有实，入者间亦有虚，此言其大概耳。言者为虚，以病气内乏，神气自
清，故惺惺而不妨于言也。不言者为实，以邪气外攻，入郁于内，故神志昏乱而不言也。缓者为虚，
以缓病来迟，正气夺而邪气微，则病渐深也。急者为实，以急病来骤，正气漓而邪气盛，则病疾速也。
诊者，按也，候也。按其外而知之，非诊脉之诊也。以诊候言之，痒者为虚，血气少而肌肉不充则
痒。痛者为实，邪气聚而营卫不和则痛。又凡虚者喜按，实者拒按，故按之而痛者为实，按之而快
者为虚也。濡者为虚，牢者为实，《脉经》引用此条，无此二句，或因上文而重出也。杨氏谓按之
皮肉柔濡者为虚，牢强者为实，似亦可解，姑存备参。
第四十八难说：人有三种虚证和三种实证，这是什么意思呢？
回答说：有脉象的虚实，有病势的虚实，有诊察的虚实。所谓脉象的虚实，脉象濡软的是虚证，脉象紧实牢硬的是实证。所谓病势的虚实，病邪由内向外出的为虚证，由外向内入的为实证；能够言语表达的是虚证，不能言语的是实证；病势缓和的是虚证，病势急骤的是实证。所谓诊察的虚实，按之柔软的是虚证，按之坚硬的是实证；感觉瘙痒的是虚证，感觉疼痛的是实证。体表疼痛而体内舒适，是外实内虚；体内疼痛而体表舒适，是内实外虚。所以称之为虚实。
虚证，是指正气空虚，正气不足。实证，是指邪气强盛，邪气有余。从脉象来说，脉象濡软细弱，所以属于虚证。脉象紧弦劲急、沉取有力，所以属于实证。然而脉象的虚实不仅仅局限于此，列举这些可以类推其他情况。从病势来说，病邪由内出外，这是五脏自生的疾病，由内部向外部发展，这就是所谓的内伤。病邪由外入内，这是五种邪气所中，由外部向内部侵袭，这就是所谓的外感。然而由内出外的病间或也有实证，由外入内的病间或也有虚证，这里说的是大概情况罢了。能够言语，是因为病气在内部匮乏，神气自然清明，所以清醒而不妨碍说话。不能言语，是因为邪气从外部攻袭，郁结在内部，所以神志昏乱而不能说话。病势缓和，是因为病来迟缓，正气被削弱而邪气微弱，那么病情就会逐渐加深。病势急骤，是因为病来突然，正气耗散而邪气旺盛，那么病情就会迅速恶化。
诊，就是按压、候察的意思。通过按压体表来了解病情，不是指诊脉的“诊”。从诊候来看，瘙痒属于虚证，因为血气少而肌肉不充盈所以发痒。疼痛属于实证，因为邪气聚集而营卫不和所以疼痛。大凡虚证喜欢按压，实证拒绝按压，所以按之疼痛的是实证，按之舒适的（快）是虚证。脉象濡软的是虚证，脉象牢硬的是实证，《脉经》引用这一条时没有这两句，可能是因为上文重复出现而产生的。杨氏认为按之皮肉柔濡的是虚证，牢硬强实的是实证，似乎也可以解释，暂且保存以供参考。
Difficulty 48 states: There are three types of deficiency and three types of excess in the human body. What does this mean?
The answer is: There is the deficiency and excess of pulse, the deficiency and excess of disease progression, and the deficiency and excess of diagnosis. Regarding the deficiency and excess of pulse, a soft (Ru) pulse indicates deficiency, while a tight (Jin) and firm (Lao) pulse indicates excess. Regarding the deficiency and excess of disease progression, outward movement indicates deficiency, and inward penetration indicates excess; ability to speak indicates deficiency, inability to speak indicates excess; a slow onset indicates deficiency, and a rapid onset indicates excess. Regarding the deficiency and excess of diagnosis, softness upon palpation indicates deficiency, and hardness upon palpation indicates excess; itching indicates deficiency, and pain indicates excess. Pain on the exterior with comfort on the interior indicates exterior excess and interior deficiency; pain on the interior with comfort on the exterior indicates interior excess and exterior deficiency. Thus, these are referred to as deficiency and excess.
Deficiency refers to emptiness, where the healthy Qi (Zheng Qi) is insufficient. Excess refers to strength, where the pathogenic factor (Xie Qi) is abundant. Speaking from the perspective of pulse, a soft and fine pulse is therefore considered deficiency. A tight, wiry, and forceful pulse, or a deep and forceful pulse, is therefore considered excess. However, the deficiency and excess of pulses are not limited to this; citing these allows for analogical reasoning. Speaking from the perspective of disease, outward movement implies deficiency, which refers to diseases originating from the five Zang organs, developing from the interior to the exterior, known as internal injury (Nei Shang). Inward penetration implies excess, which refers to being struck by the five pathogenic factors, invading from the exterior to the interior, known as external contraction (Wai Gan). However, outward-moving conditions occasionally present with excess, and inward-penetrating conditions occasionally present with deficiency; this statement covers the general principles. The ability to speak occurs because the pathogenic Qi is deficient internally, allowing the Spirit Qi (Shen Qi) to remain clear, thus maintaining lucidity without hindering speech. The inability to speak occurs because pathogenic factors attack from the exterior and stagnate within, causing confusion of the spirit and mind, leading to silence. A slow onset occurs because the disease develops gradually; when healthy Qi is depleted and pathogenic factors are weak, the disease deepens progressively. A rapid onset occurs because the disease strikes suddenly; when healthy Qi is exhausted and pathogenic factors are vigorous, the disease progresses rapidly.
"Zhen" (Diagnosis/Palpation) means pressing and observing. It refers to understanding the condition through palpating the exterior, not specifically pulse diagnosis. From the perspective of clinical observation, itching indicates deficiency, as insufficient blood and Qi fail to nourish the muscles, causing itching. Pain indicates excess, as the accumulation of pathogenic factors disrupts the harmony of Ying (Nutrient) and Wei (Defensive) Qi, causing pain. Generally, deficiency patterns welcome pressure, while excess patterns reject it; therefore, pain upon pressure indicates excess, and comfort upon pressure indicates deficiency. A soft pulse indicates deficiency, and a firm pulse indicates excess. The *Mai Jing* (Pulse Classic) cites this passage but omits these two sentences, possibly due to repetition from the preceding text. Yang Shi suggested that soft and flaccid flesh upon palpation indicates deficiency, while firm and strong flesh indicates excess, which seems also plausible; this view is preserved for reference.