While most patients complain they fail to understand doctor's use of jargon, young doctors feel frustrated when they do not know how to ask questions or provide explanations in the patients' mother tongue. The difference between professional terms and lay expressions lies not only on the linguistic precision and concision, but also the different functions each achieves. The former serves to establish medical knowledge and the latter the exchange of health information. Grounded in the idea of ”diglossia” in sociolinguistics (i.e., the distribution of high and low codes in different interactional contexts), the author suggests two discourse strategies in expressing health information to patients. In gathering health problems from patients, the use of medical jargon (i. e., high codes) is not recommended. Instead, it is suggested that doctors first separate the complicated ideas involved in a medical term into small units and then paraphrase each with common expressions (i.e., low codes). In providing a diagnosis for the patient, the introduction of professional jargon increases patient's medical knowledge which, however, can only be achieved if an explanation in common expression is provided first.