Professional text is rightly considered one of the main indicators of world scientific and technological development in the XXI century. Recently, special attention has been paid to the study of medical texts. In modern translation studies, such a rapid development of society, especially in the medical field, and the emergence of new translation studies trends, the replenishment of the terminological system with more specialized professional vocabulary is a challenge for the translator. The medical text is interesting in structure due to the category of modality, which serves as a means of expressing the author's attitude to what is written, and is considered by various researchers as a grammatical, syntactic or semantic category. In addition, linguists do not stand in solidarity on defining and classifying modality, that follows from its comprehensive study. At present, the study of modality occupies a leading place in linguistics, due to the complexity and diversity of the category. Means of modality are studied at different levels: formal-syntactic, communicative-functional, semantic-syntactic and, of course, textual. The modality of the text responds on the attitude of the author of the text, usually evaluative, to reality. The essential characteristics of the modality object itself determine the content of the modality. According to different approaches, it is divided into "external", "internal", general, voluntary, true, as well as objective-evaluative and subjective-evaluative. In our study, special attention is paid to the subjective-evaluative modality, which is necessary to express official politeness. It can be argued that the semantic basis of subjective modality influences the formation of the concept of evaluation in its broadest sense. It is not only about the logic of the presentation of information, but also the different types of emotional reaction of the person. The main linguistic means for expressing this type of modality have also been established, which include the use of modal verbs, modal words, and modal passive constructions.