, also commonly spelled ch'i, chi or ki, is a fundamental concept of everyday Chinese culture, most often defined as "air" or "breath" (for example, the colloquial Mandarin Chinese term for "weather" is tian qi, or the "breath of heaven") and, by extension, "life force" or "spiritual energy" that is part of everything that exists. References to qi or similar philosophical concepts as a type of metaphysical energy that sustains living beings are used in many belief systems.
Philosophical conceptions of qi date from the earliest recorded times in Chinese thinking. One of the important early figures in Chinese mythology is Huang Di or the Yellow Emperor. He is often considered a culture hero who collected and formalized much of what subsequently became known as traditional Chinese medicine. Although the concept of qi has been very important within all Chinese philosophies, their descriptions of qi have been varied and conflicting.
The etymological meaning of the qi ideogram in its traditional form is "steam rising from rice as it cooks" (source: Wenlin dictionary), which could be interpreted as indicating the link between matter and the energy it develops. Matter and energy are said merely to be different states of the same fundamental substance.
Theories of traditional Chinese medicine assert that the body has natural patterns of qi associated with it that circulate in channels called meridians in English. Symptoms of various illnesses are often seen as the product of disrupted or unbalanced qi movement through such channels (including blockages), deficencies or imbalances of qi, in the various organs. Traditional Chinese Medicine seeks to relieve these imbalances by adjusting the flow of qi in the body using a variety of therapeutic techniques. Some of these techniques include herbal medicines, special diets, physical training regimens (qigong), massages to clear blockages, and acupuncture, which uses fine metal needles inserted into the skin to reroute or balance qi. Traditional Asian martial arts also discuss qi. For instance, internal systems attempt to cultivate and direct qi during combat as well as to ensure proper health. Many other martial arts include some concept of qi in their philosophies.