This theory is based on ancient Chinese Taoism, views a person as an energy system in which body and mind are unified, each influencing and balancing the other. In TCM, a person's health is influenced by the flow of Qi (energy) in the body, in combination with the universal forces of Yin and Yang. If the flow of Qi is obstructed, deficient, excessive, or just unbalanced, Yin and Yang are said to be thrown out of balance causing pain and illness to occur. TCM includes Chinese herbal medicine, acupuncture and moxibustion, Qigong, Tai Chi, and diet therapy.