However, structural proteins in COVID-19 patients' red blood cells were significantly damaged . At the same time, membrane lipid remodeling and the level of RBC glycolysis intermediates increased . There are no significant changes in blood parameters such as RBC count, hematocrit or average corpuscular hemoglobin concentration, or average corpuscular volume . Notably, an increase in RDW correlates with a decrease in ventilator-free days in the intensive care unit (109). As the severity of COVID-19 increases, the distribution width of red blood cells (RDW) gradually increases(110). The phenomenon is defined by the apparent heterogeneity of red blood cell volume(111). Numerous studies have revealed that some COVID-19 patients do experience significant hemolysis problems. There is a need for a more rational method of evaluating the hemoglobin affinity argument, particularly at the microcirculation level(112). Microscopic spectrophotometry analysis revealed a significant shift in a single COVID-19 patient's red blood cell(113). Hemoglobin absorbance increases in the 420 nm wavelength range during severe SARS-CoV-2 infections(113).