寒热同形者,寒极似热,阴寒逼其微阳外越也;热极似寒,所谓热深厥深也。更有久服
温补
,清浊混处,畏寒异常,攻以寒下之剂,而阳达寒退者。前人之名论、治案伙矣。同病者,
真寒、真热二气并见也。如伤寒大青龙证,是寒束于外,卫陷于内,而化热也。其人必胃热
素盛者。太阳中 ,是先伤于暑,后伤冷水,乃寒热两感之病也。《内经》论疟,义亦如此
。此表寒里热也。须辨其浅深轻重,气分血分,而分治之。表热里寒,则有内伤生冷,外伤
烈日,发为霍乱者;瓜果酒肉,杂然并食,发为痢疾者。至于上热下寒,是肺热肾寒,内虚
之病也;亦有下受寒湿,逼阳上升者;前人皆有名论。独有上寒下热,真阳怫郁之证,近日
极多。其脉沉之见滑,或兼大;浮之见弦,或兼细。其病因,或由久受湿寒,阳气不得流通
,或因微热,过服清肃之剂。每怪前贤,绝无论及,及读许叔微破阴丹一案,乃深叹其独具
只眼也。又有气寒血热、血寒气热之辨,即仲景荣寒卫热、卫寒荣热之事也。血热则脉形缓
大,气寒则起伏不大而无力,血寒则脉形紧小,气热则来势盛大而有力矣。此亦前人之所未
及也,惟叶天士通络之说,于此等病治法甚合。吾每窃取而用之,其效殊捷。又有其人本寒
而伤于热,及本热而伤于寒,日久往往与之俱化。若初起未化,与邪盛而不化者,其治法须
仿《内经》治胜安伏之义,恐得药后复化也。
寒热同形,是指寒证与热证在表象上相似。寒极似热,是阴寒之邪逼迫体内微弱的阳气向外浮越所致;热极似寒,即所谓“热深厥深”(内热越盛,四肢厥冷越严重)。此外,还有长期服用温补药物,导致清浊之气混杂,出现异常畏寒的症状,此时若用寒凉攻下的方剂治疗,反而能使阳气通达、寒邪退去的情况。前人的著名论述和治疗医案不胜枚举。
同病,是指真寒与真热两种病气同时出现。例如伤寒的大青龙汤证,是寒邪束缚于体表,卫气郁陷于体内,从而化热。这类患者通常胃中素有积热。太阳中暍(中暑),是先受暑邪伤害,后又受冷水侵袭,属于寒热两感之病。《内经》对疟疾的论述,道理也是如此。这是表寒里热的情况。必须辨别其病位的浅深、病情的轻重,以及是在气分还是血分,从而分别施治。
表热里寒的情况,有的是因内伤生冷食物,外受烈日暴晒,引发霍乱;有的是瓜果、酒肉杂乱进食,引发痢疾。至于上热下寒,属于肺热肾寒的内虚病症;也有的是下部受寒湿侵袭,逼迫阳气上升所致;前人对此都有著名论述。唯独上寒下热,即真阳被郁遏的病证,近年来极为多见。其脉象沉取时见滑脉,或兼大脉;浮取时见弦脉,或兼细脉。其病因,或是由于长期感受湿寒,阳气不能流通;或是因为有轻微发热,却过量服用清热肃降的药物。我常常惊讶于前代贤人绝少提及此证,直到读到许叔微关于破阴丹的治疗医案,才深深赞叹他独具慧眼。
又有气寒血热、血寒气热的辨析,这也就是张仲景所说的营寒卫热、卫寒营寒的情况。血热则脉象形态缓大而有力;气寒则脉搏起伏不大且无力;血寒则脉象形态紧小;气热则来势盛大而有力。这也是前人未曾涉及的领域,只有叶天士的通络学说,对于此类疾病的治疗方法非常契合。我每每借鉴并应用他的方法,疗效特别迅速。
还有的人本身体质偏寒却伤了热邪,或者本身体质偏热却伤了寒邪,日久往往两者相互转化。如果初起尚未转化,或者邪气盛而未转化的情况,治疗方法须效仿《内经》中“治胜安伏”(控制亢盛之邪,安抚潜伏之邪)的原则,以防服药后病情再次发生转化。
"Same appearance of cold and heat" refers to situations where cold and heat syndromes present with similar manifestations. Extreme cold may resemble heat, which is caused by Yin-cold pathogenic factors forcing the faint Yang-Qi to float outward; extreme heat may resemble cold, known as "the deeper the heat, the deeper the厥 (cold limbs)." Furthermore, there are cases where long-term use of warming and tonifying herbs leads to a mixture of clear and turbid Qi, resulting in abnormal aversion to cold. In such instances, treating with cold purgative formulas can allow Yang-Qi to penetrate and cold pathogens to recede. There are numerous famous discussions and clinical records by predecessors on this topic.
"Same disease" refers to the simultaneous presence of true cold and true heat pathogenic factors. For example, the Da Qing Long Tang syndrome in Shanghan (Cold Damage) involves external constraint by cold pathogens and internal depression of Wei-Qi (Defensive Qi), leading to transformation into heat. Patients with this condition typically have a pre-existing excess of stomach heat. Taiyang Zhong Yue (Heatstroke in the Taiyang stage) occurs when one is first injured by summer-heat and subsequently exposed to cold water, constituting a disease of simultaneous cold and heat invasion. The discussion on malaria in the Neijing (Classic of Internal Medicine) follows a similar logic. This represents exterior cold and interior heat. One must distinguish the depth and severity of the condition, as well as whether it affects the Qi level or Blood level, to apply differentiated treatment.
Exterior heat and interior cold may result from internal injury due to raw and cold foods combined with external exposure to scorching sun, leading to Huoluan (Cholera-like vomiting and diarrhea); or from indiscriminate consumption of fruits, melons, wine, and meat, leading to Liji (Dysentery). As for upper heat and lower cold, this is an internal deficiency disease characterized by lung heat and kidney cold. Alternatively, it may arise from lower body exposure to cold-dampness forcing Yang-Qi to ascend. Predecessors have provided famous discussions on these scenarios. However, the syndrome of upper cold and lower heat, representing the stagnation of True Yang, has become extremely common in recent times. The pulse is slippery or large upon deep palpation, and wiry or fine upon superficial palpation. The etiology may stem from long-term exposure to cold-dampness obstructing the free flow of Yang-Qi, or from excessive use of cooling and descending agents for minor heat symptoms. I often marvel that previous sages rarely mentioned this, until I read Xu Shuwei's case record involving Po Yin Dan, at which point I deeply admired his unique insight.
There is also a distinction between Qi-cold/Blood-heat and Blood-cold/Qi-heat, which corresponds to Zhang Zhongjing's concepts of Ying-cold/Wei-heat and Wei-cold/Ying-heat. When Blood is hot, the pulse form is slow and large; when Qi is cold, the pulse fluctuation is slight and forceless; when Blood is cold, the pulse form is tight and small; when Qi is hot, the pulse momentum is grand and forceful. This area was also overlooked by predecessors, except for Ye Tianshi's theory of unblocking collaterals, which aligns very well with the treatment methods for such diseases. I frequently borrow and apply his methods, achieving remarkably swift results.
Additionally, individuals whose constitution is inherently cold but suffer from heat injury, or those whose constitution is inherently hot but suffer from cold injury, often undergo mutual transformation over time. If the initial stage has not yet transformed, or if the pathogen is strong and does not transform, the treatment method should emulate the principle of "treating the dominant to pacify the latent" from the Neijing, to prevent recurrence or transformation after medication administration.