This article discusses the epidemiology of chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD). CHF and COPD are characterized by high prevalence and high mortality, especially when they are combined. The article analyzes the general mechanisms of formation of these diseases: the relationship of COPD with cardiovascular diseases is explained by common risk factors, including smoking, physical inactivity, improper feeding and genetic predisposition. The leading role in the pathogenesis of pathologies is played by the activation and maintenance of systemic inflammation. Article presents the features of the clinical picture and the direction of the diagnostics in case of suspected combined pathology, the possibilities of modern laboratory and instrumental research methods. Diagnostics of comorbidity of CHF and COPD may be difficult, given the above common risk factors, some common pathogenesis mechanisms and similar clinical symptoms. However the caution regarding the comorbidity of the studied conditions, as well as a thorough clinical examination and the appointment of the necessary additional research methods, can reduce the number of diagnostic mistakes and improve the prognosis in such patients.