Believers in qi describe it as a vital force, with one's good health requiring its flow to be unimpeded.

Possible etymologies include the logographs 氣, 气, and 気 with various meanings ranging from "vapor" to "anger", and the English loanword qi or ch'i.

Hackett Publishing Company, Philip J. Ivanhoe, and Bryan W. Van Norden theorize that the word qi possibly came from a term that referred to "the mist that arose from heated sacrificial offerings".

Pronunciations of 氣 in Sino-Xenic borrowings include: Japanese ki, Korean gi, and Vietnamese khí.

[12] Reconstructions of the Old Chinese pronunciation of 氣 standardized to IPA transcription include: */kʰɯds/ (Zhengzhang Shangfang), */C.qʰəp-s/ (William H. Baxter and Laurent Sagart), and */kə(t)s/ (Axel Schuessler[12]).

For example, the widely known word dào 道 "the Dao; the way" graphically combines the "walk" radical 辶 with a shǒu 首 "head" phonetic.

Others are based on semantics: qīng 氫 (with a jīng 巠 phonetic, abbreviating qīng 輕 "light-weight") "hydrogen (the lightest element)" and lǜ 氯 (with a lù 彔 phonetic, abbreviating lǜ 綠 "green") "(greenish-yellow) chlorine".

The first Chinese dictionary of characters, the Shuowen Jiezi(121 CE) notes that the primary qì 气 is a pictographic character depicting 雲气 "cloudy vapors", and that the full 氣 combines 米 "rice" with the phonetic qi 气, meaning 饋客芻米 "present provisions to guests" (later disambiguated as xì 餼).

n. ① air; gas ② smell ③ spirit; vigor; morale ④ vital/material energy (in Ch[inese] metaphysics) ⑤ tone; atmosphere; attitude ⑥ anger ⑦ breath; respiration b.f. ① weather 天氣 tiānqì ② [linguistics] aspiration 送氣 sòngqì v. ① anger ② get angry ③ bully; insult.

Within the framework of Chinese thought, no notion may attain such a degree of abstraction from empirical data as to correspond perfectly to one of our modern universal concepts.

Nevertheless, the term qi comes as close as possible to constituting a generic designation equivalent to our word "energy".

By understanding the rhythm and flow of qi, they believed they could guide exercises and treatments to provide stability and longevity.

Until China came into contact with Western scientific and philosophical ideas, the Chinese had not categorized all things in terms of matter and energy.

[further explanation needed] Qi and li (理: "pattern") were 'fundamental' categories similar to matter and energy.

When he reaches old age, his xue–qi is already depleted, so he guards himself against acquisitiveness.The philosopher Mozi used the word qi to refer to noxious vapors that would eventually arise from a corpse were it not buried at a sufficient depth.

When properly nurtured, this qi was said to be capable of extending beyond the human body to reach throughout the universe.

"[21] The Guanzi essay Neiye (Inward Training) is the oldest received writing on the subject of the cultivation of vapor [qi] and meditation techniques.

Chinese people at such an early time had no concept of radiant energy, but they were aware that one can be heated by a campfire from a distance away from the fire.

150 BC) wrote in Luxuriant Dew of the Spring and Autumn Annals:[23] "The gibbon resembles a macaque, but he is larger, and his color is black.

("猿似猴。大而黑。長前臂。所以壽八百。好引氣也。") Later, the syncretic text assembled under the direction of Liu An, the Huai Nan Zi, or "Masters of Huainan", has a passage that presages most of what is given greater detail by the Neo-Confucians: Heaven (seen here as the ultimate source of all being) falls (duo 墮, i.e., descends into proto-immanence) as the formless.

The Huangdi Neijing ("The Yellow Emperor's Classic of Medicine", circa 2nd century BCE) is historically credited with first establishing the pathways, called meridians, through which qi allegedly circulates in the human body.

[25] Traditional Chinese medicine often seeks to relieve these imbalances by adjusting the circulation of qi using a variety of techniques including herbology, food therapy, physical training regimens (qigong, tai chi, and other martial arts training),[26][page needed] moxibustion, tui na, or acupuncture.

[5] A 1998 consensus statement on acupuncture by the United States National Institutes of Health noted that concepts such as qi "are difficult to reconcile with contemporary biomedical information".

[34] The traditional Chinese art of geomancy, the placement and arrangement of space called feng shui, is based on calculating the balance of qi, interactions between the five elements, yin and yang, and other factors.

The retention or dissipation of qi is believed to affect the health, wealth, energy level, luck, and many other aspects of the occupants.

Feng shui with a compass might be considered a form of divination that assesses the quality of the local environment.

[42] There is no regulation of the practicing of Reiki in the United States and generally no central world organization that has authority over it.

Martial qigong is a feature of both internal and external training systems in China[48][page needed] and other East Asian cultures.

[49][page needed] The most notable of the qi-focused "internal" force (jin) martial arts are Baguazhang, Xingyiquan, tai chi, Southern Praying Mantis, Snake Kung Fu, Southern Dragon Kung Fu, Aikido, Kendo, Hapkido, Aikijujutsu, Luohanquan, and Liuhebafa.

Demonstrations of qi or ki are popular in some martial arts and may include the unraisable body, the unbendable arm, and other feats of power.