The article is relevant in determining the role of modern Kyrgyz language as one of the ancient Turkic languages. The purpose of this article is to determine the level of words used in the modern Kyrgyz language described in the dictionary "Divanu lugati t-turk" by Mahmut Kashkari, including names of diseases, and linguistic phenomena in the transformation of words. Research objects are translated words in the M. Kashkari's dictionary. The study is based on the historical-comparative method. As a result of this study, it was found that the names of physical structures and diseases in the dictionary by M. Kashkari in the modern Kyrgyz language are subjected to phonetic changes (őt -gallbladder, kőz -eye, head -head, eyelash -eyelash, iriƞ -pus, etc.), but some of them are subjected to phonetic changes (buğın -joint, bőgőn -lump, ažaq -foot, foot, ämik -breast, ärnäk -toe, sigil -wart, etc.) and some words have other names that are not used at all (tılaq -female genitalia, ožluq -bone marrow, kősri -chest, bağıriaq -rash, etc.).