Qi, usually articulated as ch'i is a Chinese philosophical concept that has expanded in use into many meanings. Qi is commonly referred to as the life force or the energy, in humans and nature.
Chinese philosophies, have varied descriptions of what Qi is, whether it arises from matter and what are the relations between the human, individual life force and that of the environment or universe.
Qi in traditional Chinese medicine
Ancient Chinese medicine asserts that there are natural patterns of energy that circulate in channels called meridians. Blocked, or unbalanced energy movement through the body's meridians causes sickness and loss of physical and mental well being.
Curing and regulating the Qi
Many techniques, ranging from the pure meditation to the use of potions and medicines are considered by believers when trying to balance or invigorate the Qi. Traditional Herbal medicines, diets and special systems of movements are used. In the last decade, western medicine has acknowledged some of the beneficial effects of acupuncture and other TCM treatments by incorporating these treatments as supplementary to western treatments.
Does Qi really exists?
There is no concise scientific proof that supports the existence of Qi as a substance or energy passing or residing in the human body. However - as a mental concept - Qi belief and systems based on it (whether they be medical or utilitarian in nature) is beneficial and provides very good results in healing, movement and mental well being.
Qi in martial arts
Qi is an important concept in many martial arts, particularly the Chinese martial arts. Claims and proofs that using the Qi concpet can benefit the martial artist in pragmatic ways are still unproved and has led, at least in one example, to a harsh and fatal reminder of the limitations of belief systems. (see boxers' rebellion).