Discussion on "avoiding pathogenic influences and damaging winds in due season" in Huangdi Neijing based on "three deficiencies" and "eight cardinal directions"

"Avoiding pathogenic influences and damaging winds in due season" is a concise yet inclusive scripture in Huangdi Neijing that not only focuses on avoiding pathogenic qi in the four seasons but is also explained from the two perspectives of "three deficiencies" and "eight cardinal directions." First, in terms of "three deficiencies," in the year of overrestraint, we should avoid the conquest of abnormal changes of climate from the first to third qi, and avoid the retaliation of abnormal changes of climate from the fourth qi to last; second, on the first day of each lunar month and one to two days before and after, the human body is in a weak state under the influence of the moon; therefore, deficient nature pathogens should be avoided. Third, when the solar terms are exchanged, climate changes should be observed to anticipate them. In terms of "eight cardinal directions," we should prevent abnormal wind and rain, which come early or late around the eight solar terms (Beginning of Spring, the Spring Equinox, the Beginning of Summer, the Summer Solstice, the Beginning of Autumn, the Autumn Equinox, the Beginning of Winter, and the Winter Solstice). In contrast, especially on the day of the eight solar terms, the wind coming from the opposite direction of the corresponding solar terms should be paid attention to, as this wind is violent and easily opens the pores to cause disease. Therefore, it is necessary to stay indoors on such days. Additionally, the wind, coming from the rest of the six directions in addition to the direction and the opposite direction of the corresponding solar terms, on the first day of the first month of the lunar calendar, is regarded as the basis for predicting the prevalence of diseases of the coming year, which also needs special attention. Therefore, "avoiding pathogenic influences and damaging winds in due season" must be deeply interpreted to fully use the Huangdi Neijing to prevent and treat diseases.