Background and Objectives: Despite the fact that the methods of dynamic interfacial tensiometry and rheology are used to study blood and other biological fluids, in medicine there is no unified approach in the methodology of analysis and interpretation of the results. However, in some cases, the obtained numerical characteristics do not have a simple physical meaning and do not allow to evaluate the contribution of individual components and, as a consequence, it is impossible to identify the main link. Taking into account the multidirectional and nongeneralized data on rheology and due to the multicomponent and uncertain composition, there have been no successful attempts so far to create models to determine the real contribution of individual blood components. The purpose of this study is to develop a model, based on which one could obtain information about physical constants and parameters of individual plasma and/or blood serum components for medical diagnostics. Materials and Methods: The study is performed on blood samples of two human groups: group 1) 15 patients with coronary heart disease aged from 51 to 76 years; group 2) conditionally healthy volunteers (15 people) aged from 50 to 75 years. Results: For serum/plasma fractionation, a protein “desalting” method is used to obtain a fraction of low-molecular-weight metabolites. Further determination of interphase tensiometry is performed by the hanged drop method using hardware-software complex PAT-1 (“Sinterface Technologies”, Germany). The curves of the dynamic interfacial tension of the studied groups differ significantly throughout the entire time of the experiment. The average values of the dynamic interfacial tension of native serum in group 1 are noticeably lower than in the group 2 (the group of healthy volunteers). The detected change in the value of the dynamic interfacial tension may indicate an accumulation of surfactants in the serum of patients with coronary heart disease. The data obtained are in satisfactory agreement withthemathematicalmodel proposed bythe authors. Ifthe adsorption atthe beginning of the experiment is due mainly to low molecular weight compounds, then the value of the sum of the concentrations of high molecular weight compounds (after protein precipitation) should be slightly lower than the values of the corresponding indicators of the native blood samples. Conclusion: Using the obtained data of dynamic surface tension and the proposed mathematical model the following conclusions have been formulated: 1) tensiometric characteristics of blood serum for group 1 and 2 differ in dynamic and equilibrium surface tension; 2) the quantitative and qualitative contribution of the coagulation system to surface tension and the sum of concentrations of low molecular weight compounds; 3) the contribution of low molecular weight metabolites in the formation of surface tension of plasma and serum has been estimated; 4) the heterogeneity of the qualitative composition of low-molecular substances fractions in the studied groups has been shown.