经云。肾为欠为嚏。气郁于胃。故欠生焉。胃足阳明之脉。是动。则病振寒。善伸数欠。二
阳一阴发病。主惊骇。背痛。善噫善欠。
胃为二阳。肾为一阴。以胃虚气郁于中则为噫。肾虚经郁于下则为欠。内经虽以欠隶诸胃。
然必由少阴经气下郁。不能上走阳明。胃气因之不舒而频呼数欠。以泄其气。舒其经。若少阴气
不下应。胃气虽虚。郁上泄。则但呼而不欠也。
人之嚏者。阳气和利。满于心。出于鼻。故为嚏。
金匮云。夫中寒家善欠。其人清涕出。发热色和者善嚏。中寒。其人下利。以里虚也。欲嚏
不能。此人肚中寒。
中气虚寒。不能上温肺气。则善呼。不能下引肾气。则善欠。故呼欠。虽主胃气不舒。实缘
肾气郁伏所致。若中寒而加火迫津气。或风激水液。皆清涕出。纵由士虚不能御邪之故。设兼客
邪发热。而色和善嚏者。此表气尚强。逼邪
上走空窍也。亦有里虚不能拒邪而为下利者。知其人必有陈寒。无阳气以发越其邪。故欲嚏而不能也。
河间曰。嚏者鼻中因痒。而气喷作于声也。鼻为肺窍。痒为火化。外风欲入而内火拒格。故
发为嚏。有嚏则风邪随气而散。不能入伤于经。是以伤风有嚏为轻。
石顽曰。内经金匮。虽有嚏欠之因。却无方药主治。守真以伤风有嚏为轻者。其人阳气和利。
虽有风邪。自能随气鼓散。可无藉于汤药也。于此有人素蕴湿热。加以客邪。鼻塞不闻香臭。服
细辛、辛夷等药百余剂。每当微风。即嚏不已。三嚏之后。清涕如注。脑户隐隐掣痛。诸治罔效。
因思金匮中寒家清涕善嚏之说。遂取钟乳专温肺气之品。助以人参温中。黄 实卫。鹿茸固髓。
黄牛脑和丸。空腹服三十丸。饵及两月。数年之病。随手而愈。
《内经》说：肾主呵欠和打喷嚏。气郁结在胃中，所以产生呵欠。足阳明胃经发生病变时，会出现战栗发冷、喜欢伸展、频繁打呵欠的症状。“二阳”（指阳明胃与大肠）与“一阴”（指厥阴肝）同时发病，主要表现为惊骇、背痛、喜欢嗳气和打呵欠。
胃属于“二阳”，肾属于“一阴”。如果胃虚导致气郁结在中焦，就会表现为嗳气；如果肾虚导致经络之气郁结在下焦，就会表现为呵欠。《内经》虽然将呵欠归因于胃，但必定是因为少阴肾经之气郁结在下，不能上行通达于阳明胃经，导致胃气因此不舒展而频繁呼喊、多次打呵欠，以此来宣泄气机、疏通经络。如果少阴之气不能向下应合，即使胃气虚弱，气郁结在上部并试图通过呼气来宣泄，那就只会呼喊而不会打呵欠了。
人之所以打喷嚏，是因为阳气调和顺畅，充盈于心胸，出于鼻窍，所以形成喷嚏。
《金匮要略》说：患有中寒证的人喜欢打呵欠，如果其人流清鼻涕，发热且面色正常，则喜欢打喷嚏。如果中寒之人出现下利，这是因为里气虚弱。想要打喷嚏却打不出来，这是肚中有寒邪的表现。
中气虚寒，不能向上温煦肺气，就会喜欢呼喊；不能向下引动肾气，就会喜欢打呵欠。所以，呵欠虽然主要反映胃气不舒，实际上是由于肾气郁伏所致。如果是中寒证，加上火法逼迫津液和气机，或者被风邪激惹水液，都会流出清鼻涕。这纵然有土虚（脾虚）不能抵御外邪的原因，但如果兼有客邪发热，且面色平和、喜欢打喷嚏的，说明表气尚强，正气逼迫邪气向上从空窍排出。也有因为里虚不能拒邪而导致下利的情况，这说明此人必有陈旧的寒邪，没有阳气来发散驱除邪气，所以想打喷嚏却打不出来。
刘河间说：打喷嚏是因为鼻中发痒，气息喷出并发出声音。鼻是肺的窍道，痒是由火邪化生。外风想要侵入，而内火抗拒格挡，所以引发喷嚏。有喷嚏打出，风邪就会随着气机消散，不能侵入损伤经脉，所以伤风病中有喷嚏的病情较轻。
张石顽说：《内经》和《金匮要略》虽然阐述了喷嚏和呵欠的成因，却没有记载主治的方药。刘守真认为伤风有喷嚏表示病情轻，是因为患者阳气调和顺畅，虽然有风邪，自然能随着气机鼓动消散，不需要借助汤药治疗。曾有一人素体蕴藏湿热，又感受外邪，鼻塞闻不到香味和臭味，服用细辛、辛夷等药物一百多剂，每当遇到微风，就连续打喷嚏不止，打了三个喷嚏后，清鼻涕如注般流出，脑户穴处隐隐牵掣作痛，各种治疗方法都无效。于是想到《金匮要略》中关于中寒之人流清鼻涕、喜欢打喷嚏的说法，便选用钟乳石这一专门温补肺气的药材，配合人参温补中焦，黄芪固护卫气，鹿茸填补精髓，用黄牛脑调和制成丸药，空腹服用三十丸，服药两个月，数年的疾病随即痊愈。
The *Neijing* (Inner Canon) states: The Kidney governs yawning and sneezing. Qi stagnates in the Stomach, thus causing yawning. When the Foot-Yangming Stomach Meridian is affected, it manifests as chills, a desire to stretch, and frequent yawning. When "Two Yang" (referring to the Yangming Stomach and Large Intestine meridians) and "One Yin" (referring to the Jueyin Liver meridian) are simultaneously diseased, the main symptoms include fright, back pain, belching, and yawning.
The Stomach belongs to "Two Yang," and the Kidney belongs to "One Yin." If Stomach deficiency leads to Qi stagnation in the middle jiao, it manifests as belching; if Kidney deficiency leads to meridian Qi stagnation in the lower jiao, it manifests as yawning. Although the *Neijing* attributes yawning to the Stomach, it must originate from the stagnation of Shaoyin (Kidney) meridian Qi in the lower body, which fails to ascend to connect with the Yangming Stomach meridian. Consequently, Stomach Qi becomes unsmooth, leading to frequent calling out and repeated yawning to vent Qi and unblock the meridians. If Shaoyin Qi fails to descend and respond, even if Stomach Qi is deficient and stagnates upward attempting to vent through exhalation, there will be only calling out without yawning.
Sneezing occurs when Yang Qi is harmonious and smooth, filling the heart region, and emerging from the nasal orifices.
The *Jinkui Yaolue* (Essential Prescriptions of the Golden Cabinet) states: Individuals suffering from Cold-Invading Disease often yawn. If such a person has clear nasal discharge, fever, and a normal complexion, they often sneeze. If a person with Cold-Invading Disease experiences diarrhea, it is due to interior deficiency. The inability to sneeze indicates cold in the abdomen.
Middle Qi deficiency and cold fail to warm Lung Qi upward, leading to frequent calling out; they fail to draw Kidney Qi downward, leading to frequent yawning. Thus, although yawning primarily reflects unsmooth Stomach Qi, it is essentially caused by the depression of Kidney Qi. In cases of Cold-Invading Disease, if fire methods force fluids and Qi, or wind irritates water fluids, clear nasal discharge occurs. This may be partly due to Earth deficiency (Spleen deficiency) failing to resist pathogenic factors. However, if accompanied by external pathogenic heat and a normal complexion with a tendency to sneeze, it indicates that exterior Qi is still strong, forcing pathogens upward through the orifices. Conversely, interior deficiency failing to repel pathogens may lead to diarrhea, indicating the presence of chronic cold pathogens without sufficient Yang Qi to disperse them, hence the inability to sneeze.
Liu Hejian stated: Sneezing occurs because itching in the nose causes air to spray out with sound. The nose is the orifice of the Lung; itching is transformed by Fire. External Wind attempts to enter, while internal Fire resists and blocks, resulting in sneezing. With sneezing, Wind pathogens dissipate with the Qi and cannot invade or damage the meridians; therefore, sneezing in Wind-Strike indicates a milder condition.
Zhang Shiwang stated: Although the *Neijing* and *Jinkui Yaolue* explain the causes of sneezing and yawning, they do not provide specific formulas for treatment. Liu Shouzhen argued that sneezing in Wind-Strike indicates mildness because the patient's Yang Qi is harmonious and smooth; even with Wind pathogens, they naturally dissipate with the Qi, requiring no herbal decoctions. There was a case of a patient who inherently harbored Damp-Heat and contracted an external pathogen, resulting in nasal congestion and loss of smell. After taking over a hundred doses of herbs such as Xixin (Asari Radix) and Xinyi (Magnolia Flower), every slight breeze triggered incessant sneezing. After three sneezes, clear nasal discharge flowed profusely, and there was dull pulling pain at Naohu (DU16). Various treatments failed. Recalling the *Jinkui Yaolue*'s description of Cold-Invading patients with clear discharge and sneezing, I selected Zhuru (Calcitrum) to specifically warm Lung Qi, assisted by Renshen (Ginseng Radix et Rhizoma) to warm the Middle, Huangqi (Astragali Radix) to secure the Exterior, and Lurong (Cervi Cornu Pantotrichum) to consolidate Marrow. These were mixed with cattle brain and formed into pills. Taking thirty pills on an empty stomach for two months cured this multi-year illness instantly.