Library

The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: The Kidney corresponds to the bones, and its flourishing manifests in the hair. Excessive consumption of sweet flavors leads to bone pain and hair loss (Sweet flavor tonifies Spleen Earth; Spleen Earth overacts on Kidney Water, resulting in Kidney pathology). At age seven, a woman's Kidney Qi becomes substantial, her teeth change, and her hair grows. At age thirty-five (five times seven), the Yangming Meridian begins to decline, her face starts to wither, and her hair begins to fall out. At age eight, a man's Kidney Qi becomes substantial, his teeth change, and his hair grows. At age forty (five times eight), his Kidney Qi begins to decline, his hair falls out, and his teeth become dry and brittle.

The *Chushi Bingyuan* (Source Book of Diseases by Chao Yuanfang) states: The flourishing of the Foot-Shaoyang Gallbladder Meridian manifests in the beard. The flourishing of the Foot-Shaoyin Kidney Meridian manifests in the hair. The Chong and Ren Mai (Penetrating and Conception Vessels) are the seas of the twelve meridians; their branch collaterals ascend to the lips and mouth. If blood is abundant, it nourishes the hair, resulting in beautiful beard and hair; if Qi and blood are weak, and the meridians are empty and exhausted, failing to nourish and moisten, then the beard and hair will fall out. The *Neijing* states: The branch collaterals of the Chong and Ren Mai connect to the lips and mouth. Women frequently lose blood (due to monthly menstruation, hence termed "frequent blood loss"); consequently, the Chong and Ren Mai fail to nourish the lips and mouth, so beards do not grow. Eunuchs have their Zongjin (genital tendons/sinews) removed, damaging the Chong Mai; blood is lost and does not recover, internal skin binding occurs, and the lips and mouth are not nourished, so beards do not grow. What about those who have suffered no injury and have not lost blood, yet do not grow beards? This is due to congenital insufficiency. The Chong and Ren Mai are not vigorous, the Zongjin fails to form, there is Qi but no Blood, the lips and mouth are not nourished, so beards do not grow. Beards that are black and lustrous indicate excessive heat and abundant Qi; white beards indicate deficient Blood and Qi. Those with beautiful eyebrows have abundant Blood in the Taiyang Meridian; those with full cheek and chin beards have abundant Blood in the Shaoyin Meridian; those with beautiful beards have abundant Blood in the Yangming Meridian.