The study comprehensively analyzes nominative units representing the semantic field "illness" in Russian old settler dialects of Yakutia.The research material consists of lexical units extracted from the Dictionary of Russian Old Settler Dialects in the Territory of Yakutia by continuous sampling.The study identifies and systematizes the features of euphemization in the nominations of diseases, showing correlations between linguistic phenomena and the cultural and social norms governing the perception of illnesses by patients and society.Special attention is paid to the comparative analysis of the linguistic material from the Russian old settler dialects and the Yakut language, which helps identify common and different features in the linguistic worldview of these ethnic groups.The analysis of disease nominations in the Yakut language and Russian old settler dialects of Yakutia identifies similarities in attitudes towards illness, especially severe illness.Both cultures avoid direct nominations of diseases and use euphemisms, reflecting a universal fear of the unknown and the serious consequences of illnesses.