月经三旬时一下，两月并月三居经，一年一至为避年，一生不至孕暗经。
【注】女子阴类也，以血为主。其血上应太阴，下应海潮。月有盈亏，潮有朝夕。月
经三旬一下与之相符，故又谓之月水、月信也，女子月经一月一行者，其常也。或先或
后，乃其病也。然亦有两月一行，谓之并月者；有三月一行，谓之居经者；有一年一行，
谓之避年；有一生不行而依然能孕育，谓之暗经者。此所禀之不同，而亦非病，不须治也。
经期吐血或衄血，上溢妄行曰逆经。受孕行经曰垢胎，受孕下血漏胎名。
【注】妇女月经一月一下，此其常也。若经行而吐血、衄血，上溢妄行者，是谓逆经。
有受孕之后，月月行经而产子者，是谓垢胎。有受孕数月，其血忽下而胎不陨者，是谓漏
胎。此皆月经之异乎常者也。
天地温和经水安，寒凝热沸风荡然，邪入胞中任冲损，妇人经病本同参。
【注】经曰∶天地温和，则经水安静；天寒地冻，则经水凝泣；天暑地热，则经水沸
溢；卒风暴起，则经水波涌而陇起。六淫之邪入于胞中，则损伤冲任，故妇人经病本此
同参也。如寒则血凝，热则血沸，风则血荡然波涌而大下，亦犹经水之被寒、热、风而
不得安澜也。
妇人从人不专主，病多忧忿郁伤情，血之行止与顺逆，皆由一气率而行。
【注】妇人从人，凡事不得专主，忧思、忿怒、郁气所伤，故经病因于七情者居多。盖
以血之行、止、顺、逆，皆由一气率之而行也。
Menstruation occurring every thirty days is normal. If it occurs once every two months, it is called *Bingyue* (Conjoined Month); if once a year, *Bi Nian* (Avoided Year); and if menstruation never occurs throughout life yet pregnancy is still possible, it is called *An Jing* (Hidden Menses).
[Note] Women belong to the Yin category and are primarily governed by Blood. This Blood corresponds upward to Taiyin (Hand-Taiyin Lung Meridian, which governs Qi and directs all vessels) and downward to the sea tides. The moon waxes and wanes, and the tides rise and fall morning and evening. Menstruation occurring every thirty days aligns with these natural rhythms, hence it is also referred to as "Moon Water" or "Monthly Trust." For women, menstruation occurring once a month is the norm. Deviations occurring earlier or later constitute pathology. However, there are cases of menstruation occurring once every two months, termed *Bingyue*; once every three months, termed *Jujing* (Residing Menses); once a year, termed *Bi Nian*; and those who never menstruate yet can conceive, termed *An Jing*. These variations arise from individual constitutional differences and are not considered diseases, requiring no treatment.
Hematemesis or epistaxis during menstruation, characterized by upward overflow and reckless flow, is called *Nijing* (Rebellious Menses). Menstrual-like bleeding after conception is called *Goutai* (Stained Fetus); vaginal bleeding during pregnancy without fetal expulsion is called *Loutai* (Leaking Fetus).
[Note] For women, menstruation occurring once a month is the norm. If hematemesis or epistaxis occurs during the menstrual period, with blood overflowing upward recklessly, this is termed *Nijing*. Some women experience monthly bleeding after conception and successfully deliver children, known as *Goutai*. Some women suffer sudden vaginal bleeding several months into pregnancy while the fetus remains intact, known as *Loutai*. These are all abnormalities deviating from the normal menstrual pattern.
When Heaven and Earth are mild and warm, the menstrual waters remain tranquil; when cold congeals, the menstrual waters become stagnant; when heat boils, the menstrual waters overflow; when fierce storms arise suddenly, the menstrual waters surge like waves. When the Six Excesses (pathogenic factors) invade the uterus, they damage the Chong and Ren meridians; thus, the root causes of gynecological menstrual disorders are consistent with this principle. For instance, Cold causes blood coagulation, Heat causes blood boiling, and Wind causes blood to surge wildly resulting in heavy bleeding. This is analogous to menstrual waters being disturbed by Cold, Heat, and Wind, failing to remain calm.
Women often depend on others and lack autonomy; their illnesses frequently stem from emotional injuries due to worry, anger, and depression. The movement, cessation, smoothness, and rebellion of Blood are all directed by the governing influence of Qi.
[Note] Women traditionally subordinate themselves and may not have full autonomy, making them susceptible to injury from worry, thought, anger, and qi stagnation. Consequently, most menstrual disorders originate from the Seven Emotions (internal pathogenic emotions). Generally, the flow, stoppage, smoothness, and rebellion of Blood are all governed and propelled by Qi.