1. Wind (Feng 风):

• Characteristics: Associated with movement, change, and instability. Wind is considered a primary factor that can carry other pathogenic influences into the body.
• Effects on the Body: Sudden onset of symptoms, migratory pain, dizziness, tremors, and itching.
• Related Season:
• Affected Areas: Often invades the upper body and the surface, such as the skin and respiratory system.

2. Cold (Han 寒):

• Characteristics: Represents contraction and stagnation. Cold slows down circulation and energy flow (Qi).
• Effects on the Body: Chills, aversion to cold, stiffness, joint pain, and cramping.
• Related Season:
• Affected Areas: Tends to affect the joints, muscles, and digestive system.

3. Heat/Fire (Re/Huo 热/火):

• Characteristics: Represents excessive Yang energy, leading to inflammation and overactivity.
• Effects on the Body: High fever, thirst, restlessness, irritability, red skin, and rashes.
• Related Season:
• Affected Areas: Affects the skin, blood, and internal organs, often causing symptoms of inflammation.

4. Dampness (Shi 湿):

• Characteristics: Represents heaviness and stagnation. Dampness can obstruct the flow of Qi and fluids.
• Effects on the Body: Feeling of heaviness, swelling, diarrhea, and sticky or greasy discharges.
• Related Season: Late summer.
• Affected Areas: Often affects the digestive system, joints, and lower body.

5. Dryness (Zao 燥):

• Characteristics: Represents a lack of moisture. Dryness can damage bodily fluids.
• Effects on the Body: Dry skin, dry throat, dry cough, and constipation.
• Related Season:
• Affected Areas: Affects the lungs and the skin.

6. Summer Heat (Shu 暑):

• Characteristics: Unique to summer, this factor represents extreme heat combined with dampness.
• Effects on the Body: High fever, profuse sweating, fatigue, dizziness, and dehydration.
• Related Season:
• Affected Areas: Affects the body’s Qi and fluids, leading to heat exhaustion or heatstroke.

7. Phlegm (Tan 痰):

• Characteristics: Although not strictly an external factor, phlegm results from the interaction of external factors with internal imbalances, particularly Dampness.
• Effects on the Body: Cough with mucus, nasal congestion, and nodules.
• Relation to Other Factors: Often paired with Dampness or Cold.

8. Stagnation/Stasis (Yu 瘀):

• Characteristics: Stagnation of Qi or Blood caused by internal or external factors, including trauma.
• Effects on the Body: Pain, swelling, or bruising.

Key Points:

• The Eight Exogenous Factors are seen as influences that disrupt the balance of Yin and Yang and the flow of Qi and Blood.
• The body’s defensive energy (Wei Qi) plays a critical role in resisting these influences. If Wei Qi is weak, these factors can penetrate deeper, causing more severe illnesses.
• Treatment focuses on expelling these influences from the body and restoring balance using modalities like acupuncture, herbal medicine, dietary therapy, and Qi Gong.

These factors are metaphorical as much as they are literal, reflecting the integration of environmental, emotional, and physical health in CCM.