The possibility of using laser interference microscopy to explore the morphological and functional state of erythrocytes was studied. The possibilities of this method based on the rapid determination of the structure and physiological state of erythrocytes were shown. The analysis of erythrocytes by laser interference microscopy showed that erythrocytes have a typical biconcave discocyte shape. On erythrocytes’ surface, there is a slight heterogeneity due to the presence of membrane-bound proteins. The impact on erythrocytes of stress hormones caused changes in erythrocyte surface that were different from physiologically normal. Numerous loosening of the structure appeared on cell surface during erythrocyte incubation with cortisol. Incubation of cells with adrenaline caused a greater effect of erythrocyte membranes deformation which was expressed by the appearance of convex seals and spicules on the surface. The molecular mechanisms of membrane modifications arising under the action of adrenaline and cortisol were discussed. The results of the work may be interesting both for basic research of erythrocyte properties and for practical medicine.