The phenomenon of no syndrome to differentiate poses a challenge to the clinical diagnosis and treatment of traditional Chinese medicine（ TCM）

and there are many reasons for its formation. It is believed that the direct reason is the lack of symptom groups

and the root cause is the careless and inattentive of the four diagnostic methods. It is not that the symptom group does not exist

but that the Chinese medicine practitioners fail to collect it.Studying the four diagnostic methods

the constitution differentiation

testing syndrome by formula and the method of attaching importance to the change of pathogenesis contained in the Treatise on Febrile and Miscellaneous Diseases（ 《伤寒杂病论》） can effectively solve the problem of undocumented discernment.