As it predates modern medicine the philosophy of Chinese medicine is described in a pre-scientific manner.  Health occurs when the body is in balance of yin yang.  Important in acupuncture if the free flow of Qi(vital energy) “Vital Energy” in acupuncture is virtually a metaphor for “Blood”.  Acupuncture is said to regulate the flow of blood, draining areas with too much, promoting it where there is not enough and creating better movement where these is stagnation.

Acupuncture patients often claim to feel a sensation known in Chinese as de qi ("obtaining the Qi" or "arrival of the Qi"). This sensation was considered evidence of locating the desired pressure point. (There are electronic devices available which will claim ability to determine such points)

Traditional Chinese Medicine addresses "patterns of disharmony" rather than biomedical diagnoses - however medical practioners trainer in Traditional Chinese Medicine have observed relationships between the two. A given Traditional Chinese Medicine pattern of disharmony may be reflected in a certain range of biomedical diagnoses: For example, the pattern called Deficiency of Spleen Qi could manifest as chronic fatigue, diarrhea or uterine prolapse. Likewise, a population of patients with a given biomedical diagnosis may have varying Traditional Chinese Medicine patterns.

Classically, clinical acupuncture treatment is highly individualized and based on ancient philosphies as well as subjective and intuitive impressions, and not on controlled scientific research.