哮喘夜间发作病因病机探讨

哮喘常在夜间发作、加重或导致猝死,从阴阳变化、经脉流注及气机升降等角度探讨其病因病机,认为夜间阴盛而阳虚,痰为阴邪,同气相求,夜间痰邪偏盛,阻塞气道,使肺气宣发肃降失常,引发哮喘;夜间卫气入里,无力御邪,白天接触的过敏原等外来之邪易在夜间袭肺而致哮喘发作;肺主寅时,寅时阳始升,阴始衰,此时卫阳较弱,寒邪较盛,邪胜正虚,故易发病;肺胃同主降气,哮喘患者睡眠时由于体位的改变,易致胃气上逆,上传于肺,令肺气肃降失常,上逆为咳、痰、喘。

Etiology and Pathogenesis of Asthma Attacking at Night

Asthma usually occurs,aggravates or even causes sudden death at night. The etiology and pathogenesis were discussed from the perspectives of Yin-Yang changes,meridian circulations and the ascending and descending of Qi activities. It was believed that there were overabundant Yin and deficient Yang at night and phlegm was caused by Yin pathogen,combining both the internal and external pathogenic factors.The excessive phlegm blocking the airway and causing abnormal dispersing and descending of lung Qi triggered asthma. At night,the defensive Qi entered the interior,it could not defend against pathogenic factors.As a result,pathogenic factors like allergen which patients were exposed to in the daytime were inclined to attack the lung and trigger asthma. From 3 a.m. to 5 a.m. it was the main time for the nourishment of lung. During this time,Yang began to be excessive and Yin deficient. Therefore,the defensive Yang was weaker while the pathogenic cold was stronger. As the pathogenic Qi was stronger than the healthy Qi,asthma easily occurred. Both the lung and stomach governing the descending of Qi,when asthmatic patients were sleeping,their stomach Qi tended to ascend to the lung because of changes of their body position,leading to the abnormal descending of lung Qi,which later ascending to trigger cough,phlegm and asthma.