RESUMEN
In real life,vague expression is ubiquitous in any nation and any language.Medical English,as a branch of English for Science and Technology ( EST ),is typical in accuracy of word use.However,like other kind of language,it adopts vague expression,too.Vague expression plays an important role in medical practice.In communication of medical practitioners and patients,appropriate vague expression will improve language expression and communication efficiency.In medical English,the vague words that express approximate,presuming,or uncertain meaning are usually used to replace the exact meaning words.The correspondent translation methods such as literal translation,meaning translation,specialization etc can be used according to the different context.