“Bi” refers to obstruction and blockage. Bi syndrome is a general term for a class of diseases in which the muscles, skin, and meridians are invaded by external pathogenic factors, leading to obstruction of qi and blood, and resulting in pain, soreness, numbness, and difficulty in flexing and extending the tendons, bones, joints, and muscles. *The Plain Questions: Treatise on Bi Syndrome* states: “When the three pathogenic factors—wind, cold, and dampness—combine, they give rise to Bi syndrome. When wind predominates, it manifests as wandering Bi; when cold predominates, it manifests as painful Bi; and when dampness predominates, it manifests as fixed Bi.”
In modern medicine, conditions such as rheumatic fever, gout, rheumatism, rheumatoid arthritis, sciatica, and lumbar muscle strain fall within the scope of Bi syndrome.
I. Etiology and Pathogenesis
On the one hand, there is a deficiency of Zheng Qi, resulting in an unstable defensive layer; on the other hand, external pathogenic factors of wind, cold, and dampness (or damp-heat) invade the body, obstructing the flow of Qi and blood in the meridians.
Wandering Bi (Xing Bi): Predominantly wind pathogen: Joint pain that moves unpredictably.
Painful Bi (Tong Bi): Predominantly cold pathogen: Severe, cold joint pain that worsens with cold and improves with warmth.
Fixed Bi (Zhuo Bi): Predominantly damp pathogenic factors; the joints feel achy, heavy, and fixed.
Heat Bi (Re Bi): Damp-heat; the joints are red, swollen, hot, and painful.
II. Differential Diagnosis and Treatment
1. Wandering Bi (Xing Bi): Disperse wind and unblock the meridians; dispel cold and drain dampness; use Jian Bi Decoction with modifications.
2. Painful Bi (Tong Bi): Use pungent-warm herbs to dispel cold, eliminate wind, and transform dampness; modify Wu Tou Decoction. For chronic Bi with deficiency of qi and blood, use Du Huo Ji Sheng Decoction to fortify the body’s defenses and expel pathogens.
3. Stagnant Bi (Zhuo Bi): Strengthen the spleen and dry dampness; eliminate wind and dispel cold; modify Coix Seed Decoction.
In cases of chronic bi syndrome with deficiency of qi, blood, liver, and kidney, leading to joint contractures and deformities, treatment should focus on tonifying qi, nourishing blood, and tonifying the liver and kidneys; for cases with spinal hypertrophy and ankylosis, apply warming and tonifying agents to the Governor Vessel. Regardless of the type, treatment must always include promoting blood circulation and unblocking the meridians.
4. Heat-Bi: Cool the blood and clear toxins; disperse wind and transform dampness; use Modified Bai Hu Jia Gui Zhi Decoction.
Modern Medicine: Penicillin and salicylate preparations are used for rheumatic fever; gout is treated symptomatically; aspirin, indomethacin, and corticosteroids are used for rheumatoid arthritis; these are combined with acupuncture, massage, and physical therapy.
III. Prevention
Avoid sitting or lying on damp ground, getting caught in the rain, or wading through water; avoid excessive fatigue; practice Tai Chi and Qigong regularly; take appropriate tonic Chinese herbal medicines to boost immunity; seek prompt treatment at the earliest signs of the disease.