Traditional Chinese medicine is largely based on the philosophical concept that the human body is a small universe with a set of complete and sophisticated interconnected systems, and that those systems usually work in balance to maintain the healthy function of the human body. The balance of yin and yang is considered with respect to qi ("breath", "life force", or "spiritual energy"), blood, jing ("kidney essence", including "semen"), other bodily fluids, the Wu Xing, emotions, and the soul or spirit (shen). TCM has a unique model of the body, notably concerned with the meridian system. Unlike the Western anatomical model which divides the physical body into parts, the Chinese model is more concerned with function. Thus, the TCM spleen is not a specific piece of flesh, but an aspect of function related to transformation and transportation within the body, and of the mental functions of thinking and studying.

There are significant regional and philosophical differences between practitioners and schools which in turn can lead to differences in practice and theory.

Theories invoked to describe the human body in TCM include:

• Channels, also known as "meridians"
• Wu Xing
• Qi
• Three jiaos also known as the Triple Burner, the Triple Warmer or the Triple Energiser
• Yin and Yang
• Zang and Fu

The Yin/Yang and five element theories may be applied to a variety of systems other than the human body, whereas Zang Fu theory, meridian theory and three-jiao (Triple warmer) theories are more specific.

There are also separate models that apply to specific pathological influences, such as the Four stages theory of the progression of warm diseases, the Six levels theory of the penetration of cold diseases, and the Eight principles system of disease classification.