Kidney Jing controls the eight year cycles in men and is the root of all sexual development, fertility and libido. Jing is expressed through Kidney Qi and this controls of the ‘two lower openings’ and dominates the function of the urethra and testes. The Su Wen Chapter 1:
‘at the age of 16 a man’s Kidney Qi becomes abundant and his sexual function begins to develop. He is filled with semen that he can ejaculate. When he has sexual intercourse with a woman she can have children’.
A man’s semen is an outward manifestation of his Kidney Qi and Jing, and his ability to sexually perform is a manifestation of his Kidney Qi, Yin and Yang. There are two ways for Jing deficiency to develop;
i Thanks to Steve Clancy’s “Notes on the treatment of male infertility” JCM; No73. Oct 2003 p46-50