Localization of community-acquired pneumonia (CAP) is its independent clinical sign which has not received proper coverage in the medical literature. The aim of the study is to compare the topical and clinical characteristics of unilateral lobar and segmental CAP in young men. Materials and methods: topical and clinical features of lobar, bi- and monosegmental CAP were studied in 6332 young military men. It was found out that monosegmental CAPs (mCAP) are more variable in their clinical and

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... ratory manifestations than their bisegamental and lobar variants not identified at the segmental level. The frequency of occurrence of mCAP of a specific localization directly correlates with the frequency of sputum expectoration, the severity of systemic and local neutrophilic inflammation. The 5th and 10th segments of both lungs are the zones of the most frequent localization of mCAP associated with a relatively high severity of systemic neutrophil reaction, and the 6th and 8th segments are the zones of a relatively longer course of mCAP and the predominance of signs of local inflammation. In bisegmental CAP, there is a general trend of a more pronounced systemic inflammatory response to the criterion of blood neutrophils level than in mCAP. The revealed regularities can contribute to a more accurate prediction of the mCAP course in the population of young men.