Pathogenic Factors
Cold
Cold is a Yin factor, damaging the Yang functions of the body. A relative Yang Deficiency accompanied by Cold-signs is the consequence. Cold or Yang Deficiency slow down the metabolism. Cold impedes the flow of Yin and Yang and leads to stagnation or disturbances of the circulation and this could cause pain. Cold inhibits the warming function of Yang.

Cold can be divided into external Cold and internal Cold:
External Cold External Cold is caused by cold climate, or cold foods and iced beverages. It can manifest in the body-surface and can attack joints, muscles or Channels. External Cold corresponds to Excess Cold.
Internal Cold Internal Cold is further divided into Deficient Cold and Excess Cold: Deficient Cold: The basis of Deficient Cold is Yang Deficiency with the corresponding symptoms. It usually originates from Yang Deficiency of the Lungs, Spleen or Kidneys and increases the person's sensitivity to external Cold. Excess Cold: Internal Excess Cold can be caused by cold climate or cold foods and iced beverages, which attack the Zang-Fu organs. It corresponds to Yin Excess. Internal Excess Cold damages Yang and can lead to Yang Deficiency.
TCM Information: Symptoms, causes, treatment tips, root and branch, point-combination