 Extracellular vesicles, EVs, are small particles released by cells into bodily fluids such as blood or urine. They contain important biological information which can be used to diagnose diseases. EVs have been shown to be effective biomarkers for disease diagnosis because they are easy to collect and analyze. This review discusses the various methods for isolating EVs from bodily fluids and the techniques for analyzing them. It also examines the advantages, challenges, and potential applications of EV based in vitro diagnosis. This article was authored by Xu Yisong, Ling Zou, Chen Wang and others.