“…12 , 13 Colonnello and Jannini proposed that according to the Chinese philosophical concept of yin and yang, women are regarded as an inexhaustible source of yin (ie, negative, passive, weak, destructive, cold forces identified with the female figure and the night), while men are thought to possess only a limited supply of yang (ie, positive, active, strong, constructive, warm forces identified with the male figure and the day) and that masturbation could cause a loss of yang, which might jeopardize the male's vitality. 14 In Taoist medical philosophy, jing (精; ie, sperm, spiritual energy) resides in the kidneys. Loss of sperm is believed to damage one's health because the reproductive and sexual systems are linked with this spiritual energy, whose loss could result in a sexual performance-related syndrome called shenkui (ie, 肾亏; kidney deficiency).…”