Temple Blog biological rhythm in TCM
The “harmony between human and nature” is rooted in traditional Chinese philosophy. In Traditional Chinese Medicine (TCM), the body’s biological rhythm synchronizes with natural rhythms. It is a phenomenon observed in vital activities of living beings, endowing them with the capability of adaptation and synchronization to the environment’s natural rhythms such as daily (circadian), lunar (syzygial rhythm) and seasonal rhythm.
Isomorphism between humans and nature represents the compatibility between structure and composition. The five Zang organs (heart, lung, liver, spleen, and kidney) are compatible with the five musical scales of heaven (Gong 宮[do], Shang 商[re], Jiao 角[mi], Zhi 徵[so] and Yu 羽[la]). Six Fu organs (gallbladder, stomach, small intestine, large intestine, urinary bladder, and san jiao) are compatible with the six tunes of heaven. The 365 acupuncture points are compatible with the 365 days in a year. The knees and shoulders are compatible with the mountains, the armpit and the popliteal sections are compatible with the valleys. The 12 meridians are compatible with 12 rivers. Nature’s rhythm is observed in the human body. Therefore, the isomorphism between humans and nature is a TCM explanation of the biological rhythms.
Virtues between humans and nature. The Five Elements (wood, fire, earth, water, and metal) can drive Five Positions to generate coldness, heat, dryness, wetness and wind. The five Zang organs metabolize the five Qi to create emotions such as sadness, fear, anger, happiness and worry. The heart, liver, spleen, lung, and kidney functions correlate with generation, growth, metabolism, collection, and storage.
Interaction between humans and heaven, such as the individual system of its own, humans and nature are open but not closed, with the mutual exchange of information, energy, and influences. Heaven Qi is transmitted to Lung, Earth Qi to the throat, Wind Qi to the Liver, Thunder Qi to the Heart, Grain Qi to Spleen and Rain Qi to the Kidney. The sages cultivate Yang energy during spring and summer and Yin energy during autumn and winter. Interaction between humans and heaven is the theoretical foundation and approach to applying biological rhythm to practice.
Biological rhythms are inherent bodily functions similar to natural rhythms.
The circadian rhythm is part of the operation of Ying Qi and Wei Qi. Ying Qi circulates within the pulse, and Wei Qi circulates out of the pulse, and they circulate continuously. Ying Qi has the circulating rule of 50 cycles along the body within 24 hours. Wei Qi circulates along the external body (Yang) during daytime for 25 circles and the internal body (Yin) during the night for 25 circles. The Wei Qi circulation dominates the sleeping and awake cycle. The daily rhythm imitates the four seasons: morning (spring), noon (summer), sunset (autumn) and midnight (winter). Within the biological rhythm, Qi emerges in the morning, grows at noon, declines in the evening and enters organs at midnight.
The syzygial rhythm is embodied in the prosperity-decline variation of Qi and blood. The accumulation of blood Qi and circulation of Wei Qi start from the crescent; at the full moon, blood Qi is substantiated, and muscles strengthened; at the wane, muscles and meridians are weakened, Wei Qi is gone, and the figure exists alone without essence. At the full moon, seawater flushes to the west, and the Qi and blood accumulate, strengthening the muscles and hair, tightening the skin, and compacting, but at the wane, seawater flushes to the east, and Qi and blood are weak, with Wei Qi gone, weakening and thinning the muscles and hair, flabby skin, and open texture. The moon’s phases must correlate with the prosperity-decline of blood and Qi.
The seasonal rhythms are the biological rhythm discussed most in Huangdi’s Canon of Medicine and are embodied in the rotated duties of the Five Zang organs. The liver is on duty in spring, the heart in summer, the lung in autumn and the kidney in winter. Due to the Five Zang organs taking turns to be on duty, pulse manifestation also shows periodical changes, including pulse in the spring-like string, summer flood, autumn hair and winter stone, based on which humans also show corresponding vulnerability to certain diseases. The rhythm that the Five Zang organs take a turn on duty is an essential idea concerning rhythm in TCM. The seasonal rhythm contains a group of complex causalities. It is fulfilled through highly orderly cooperation between multiple functions of creatures and is hard to understand if a single cause is isolated.
Regarding the seasonal rhythm, there are many other patterns described in Huangdi’s Canon of Medicine besides the rule of Five Zang:
- Qi is in the liver at lunar months 1 and 2;
- Qin the spleen at lunar months 3 and 4;
- Qi in the head at lunar months 5 and 6;
- Qi in the lung at lunar months 7 and 8;
- Qi in the heart at lunar months 9 and 10;
- Qi in the kidneys in the lunar months 11 and 12.
In addition, besides the significant biological rhythms of the day, month and year, the 10-day rhythm is also recorded in Huangdi’s Canon of Medicine. TCM focus primarily on the circadian and seasonal rhythm.