This article explores the potential of non-invasive measurement for elevated levels of erythrocyte aggregation in vivo, which have been correlated with a higher risk of inflammatory processes. The study proposes utilizing a dynamic light scattering approach to measure aggregability. The sensor modules, referred to as “mDLS,” comprise VCSEL and two photodiodes. Two of these modules are placed on an inflatable transparent cuff, which is then fitted to the subject’s finger root, with one sensor module positioned on each side. By temporarily halting blood flow for one minute using over-systolic inflation of the cuff, signals from both sensors are recorded. The study involved three distinct groups of subjects: a control group consisting of 65 individuals, a group of 29 hospitalized COVID-19 patients, and a group of 34 hospitalized patients with inflammatory diseases. Through experimental results, significant differences in signal kinetic behavior were observed between the control group and the two other groups. These differences were attributed to the rate of red blood cell (RBC) aggregation, which is closely associated with inflammation. Overall, the study emphasizes the potential of non-invasive diagnostic tools in evaluating inflammatory processes by analyzing RBC aggregation.