灵枢经·论痛 Discourse on Pain
黄帝问于少俞曰：筋骨之强弱，肌肉之坚脆，皮肤之厚薄，腠理之疏密，各不同，其于针石火焫之痛何如？肠胃之厚薄坚脆亦不等，其于毒药何如？愿尽闻之。少俞曰：人之骨强、筋弱、肉缓、皮肤厚者，耐痛，其于针石之痛火焫亦然。
黄帝曰：其耐火焫者，何以知之？少俞答曰：加以黑色而美骨者，耐火焫。黄帝曰：其不耐针石之痛者，何以知之？少俞曰：坚肉薄皮者，不耐针石之痛，于火焫亦然。
黄帝曰：人之病，或同时而伤，或易已，或难已，其故何如？少俞曰：同时而伤，其身多热者，易已；多寒者，难已。
黄帝曰：人之胜毒，何以知之？少俞曰：胃厚、色黑、大骨及肥者，皆胜毒；故其瘦而薄胃者，皆不胜毒也。
Huangdi asked Shaoyu, saying: 'The strength or weakness of the sinews and bones, the firmness or fragility of the muscles and flesh, the thickness or thinness of the skin, and the looseness or density of the interstitial texture all differ from person to person — how does this affect the pain of needling, stone therapy, and cauterization? The thickness, thinness, firmness, and fragility of the intestines and stomach also differ — how does this affect the response to toxic medicinals? I wish to hear it all.' Shaoyu said: 'A person whose bones are strong, sinews weak, flesh relaxed, and skin thick can endure pain; the same holds true for the pain of needling, stone therapy, and cauterization.'
Huangdi said: 'How can one know whether a person can endure cauterization?' Shaoyu answered: 'A person who, in addition, has a black complexion and well-formed bones can endure cauterization.' Huangdi said: 'How can one know whether a person cannot endure the pain of needling and stone therapy?' Shaoyu said: 'A person with firm flesh and thin skin cannot endure the pain of needling and stone therapy, and the same holds true for cauterization.'
Huangdi said: 'When people fall ill, some are injured at the same time, yet some recover easily while others recover with difficulty — what is the reason for this?' Shaoyu said: 'Among those injured at the same time, those whose bodies run more toward heat recover easily; those whose bodies run more toward cold recover with difficulty.'
Huangdi said: 'How can one know whether a person can tolerate toxic medicinals?' Shaoyu said: 'Those with a thick stomach, a black complexion, large bones, and a stout build can all tolerate toxic medicinals; thus those who are thin and have a thin stomach cannot tolerate toxic medicinals.'