Latent evil refers that one patient suffer from evil-Qi

which hides in the body and causes symptoms in a prolonged pattern. It is of great significance for preventing and controlling chronic diseases to put forward the theory of latent evil. Based on characteristics of latent evil and the application of latent evil theory

this article takes pediatric bronchial asthma for example

and puts forward that "latent wind"and "latent phlegm"are the perennial root of pediatric bronchial asthma. The article also discusses how to use latent evil theory to guide the prevention and treatment of pediatric bronchial asthma

so as to provide an example for the prevention and treatment of other chronic diseases and provide a feasible approach for "preventive treatment of disease"theory of Chinese medicine.