Library

The etiology of Bi syndrome (Bi Syndrome, obstruction syndrome) lies in the mixed invasion of Wind, Cold, and Dampness pathogens. The Five Bi syndromes refer to Pi Bi (Skin Bi), Mai Bi (Vessel Bi), Ji Bi (Muscle Bi), Jin Bi (Tendon Bi), and Gu Bi (Bone Bi). When Wind pathogen predominates, it is called Xing Bi (Wandering Bi); when Cold pathogen predominates, it is called Tong Bi (Painful Bi); when Dampness pathogen predominates, it is called Zhuo Bi (Fixed/Heavy Bi).

Symptoms include numbness of the skin, stiffness of the muscles, changes in the color of the vessels, contraction of tendons, and heaviness of the bones, which occur upon exposure to pathogens. If exposed to pathogens again, the disease may enter the Zang-Fu organs. Zhou Bi (Generalized Bi) shares similarities with Mai Bi regarding the location of pathology, but its pain is fixed in place, unlike Mai Bi which shifts from left to right.

[Note] The cause of the Three Bi syndromes is the complex interaction of Wind, Cold, and Dampness pathogens. When Wind pathogen predominates, the pain migrates; hence it is called Xing Bi (Wandering Bi). When Cold pathogen predominates, the pain is severe and bitter; hence it is called Tong Bi (Painful Bi). When Dampness pathogen predominates, the pain is heavy and fixed; hence it is called Zhuo Bi (Fixed Bi). These are named according to their etiological factors, collectively referred to as the Three Bi syndromes.

There is also the term "Five Bi," referring to Bi syndromes affecting the Skin, Vessels, Muscles, Tendons, and Bones. If these pathogens are encountered in Autumn, it forms Pi Bi (Skin Bi), where the skin is numb but still retains slight sensation of pain and itching. If encountered in Summer, it forms Mai Bi (Vessel Bi), where blood circulation within the vessels is impaired, leading to changes in complexion or vessel color. If encountered in Late Summer, it forms Ji Bi (Muscle Bi), where the muscles become hard and numb, losing sensation of pain and itching. If encountered in Spring, it forms Jin Bi (Tendon Bi), characterized by tendon contraction, joint pain, and inability to flex or extend. If encountered in Winter, it forms Gu Bi (Bone Bi), characterized by heavy, sore bones and inability to lift or move them.

"Entering the Zang-Fu organs" refers to the internal transmission of Bi pathogens to the Five Zang organs. If Pi Bi persists and is re-exposed to pathogens, it transmits internally to the Lung, forming Fei Bi (Lung Bi). If Mai Bi persists and is re-exposed to pathogens, it transmits internally to the Heart, forming Xin Bi (Heart Bi). If Ji Bi persists and is re-exposed to pathogens, it transmits internally to the Spleen, forming Pi Bi (Spleen Bi). If Jin Bi persists and is re-exposed to pathogens, it transmits internally to the Liver, forming Gan Bi (Liver Bi). If Gu Bi persists and is re-exposed to pathogens, it transmits internally to the Kidney, forming Shen Bi (Kidney Bi). These are named based on the season of pathogen exposure and the affected anatomical site, collectively known as the Five Bi syndromes.

The "pathogens" mentioned refer to the repeated exposure to Wind, Cold, and Dampness. Zhou Bi (Generalized Bi) also occurs within the blood vessels, moving up and down along the meridians; thus, it resembles Mai Bi (Vessel Bi). However, Zhou Bi has a fixed location of pain, whereas Mai Bi shifts from side to side. In modern times, conditions such as Gout (Tong Feng), Flowing Fire (Liu Huo), and Li Jie Feng (Inter-articular Wind) are considered common names for Xing Bi (Wandering Bi).