 In the allegory, these symptoms can occur because one or more of those climatic factors (called , "the six qi") were able to invade the body surface and to proceed to the interior.This is sometimes used to draw causal relationships (i.e., prior exposure to wind/cold/etc.is identified as the cause of a disease), while other authors explicitly deny a direct cause-effect relationship between weather conditions and disease, pointing out that the Six Excesses are primarily descriptions of a certain combination of symptoms translated into a pattern of disharmony.