Regulating Yin and Yang
Yin and yang refer to qi, blood, body fluids and visceral essence in the human body. Normal physiological activities depend on the balance between yin and yang. The excess or deficiency of yin or yang will inevitably lead to dysfunction of certain organs and cause disease. The basic principle of acupuncture and moxibustion therapy is to regulate yin and yang and restore their coordination. That is also the therapeutic effect of acupuncture and moxibustion therapy. There are several conditions of imbalance of yin and yang. Preponderance of yin and yang, decline of yin and yang, and asthenia of both yin and yang are the basic manifestations in the disorder of yin and yang.
So, different therapeutic methods are used in the treatment of such pathological changes with acupuncture and moxibustion therapy. For example, heat syndrome due to yang predomination should be treated by reducing yang-heat while cold syndrome caused by yin predomination should be treated by warming and dispersing yin-cold. Asthenia-cold syndrome due to failure of yang astehnia to control yin should be treated by strengthening yang while asthenia-heat syndrome due to yin asthenia and yarn sthenia should be treated by reinforcing yin. Asthenia of both yin and yang should be treated by reinforcing both yin and yang.

Reinforcing Healthy Qi
The occurrence and development of a disease is the result of pathogenic factors that impair the human body and healthy qi that fails to control pathogenic factors. Therefore strengthening healthy qi and eliminating pathogenic factors is the basic therapeutic principle of acupuncture and moxibustion therapy. The basic method is to reinforce asthenia and reduce sthenia. Asthenia syndrome due to deficiency of healthy qi should be treated by strengthening healthy qi while sthenia syndrome due to excess of pathogenic factors should be treated by reducing therapy. The syndromes complicated with both asthenia and sthenia should be treated with both the reinforcing and reducing methods with modification according to the pathological conditions.

Essential Aspect
The causes, pathological changes and manifestations of a disease are complicated. So treatment should concentrate on the nature and main pathological changes of the disease. For example, headache due to hyperactivity of liver-yang should be treated by soothing the liver to suppress yang with the selection of acupoints on the liver and gallbladder meridians; while headache due to asthenia of qi and blood should be treated by nourishing qi and blood with the selection of acupoints on the conception and governor vessels as well as Back-Shu points.
However, for the treatment of severe urgent diseases, expectant treatment is required. For example, the treatment of syncope is to needle Shuigou (GV 26), Suliao(GV 25), Hegu (LI 4) and Zhongchong (PC 9) first. When the symptoms are alleviated, other therapeutic methods can be used to deal with the cause of the disease.

Individual Conditions
The therapeutic method of acupuncture and moxibustion should suit the individual conditions of patients. Due to difference in age, sex and constitution, patients differ in the conditions of qi and blood, yin and yang as well as response and tolerance to acupuncture and moxibustion stimulation. That is why the acupuncture and moxibustion methods vary according to the conditions of the patients. For example, the treatment of infants re-quires short and thin needles, shallow insertion, short retention or no retention of the needles; while the treatment of the aged or patients with poor constitution requires gentle and slight manipulations.