Laboratory medicine in spaceflight missions: a narrative review

Background and Objective: Space biomedicine is an expanding interdisciplinary field focused on developing protocols and tools to establish appropriate Laboratory Medicine procedures. The increasing frequency of spaceflight missions, involving both professional astronauts and space tourists, requires safeguarding health and performance, particularly during prolonged stays distant from Earth. Consequently, the development of diagnostic devices and medical countermeasures has become a priority. This narrative review aims to summarize challenges and advances in diagnostic technologies for human spaceflight, emphasizing long-duration missions and astronaut health. Methods: We conducted a literature search in PubMed for publications in English. Search terms included "laboratory medicine in space" AND "analytical assays" AND "space biomedicine" AND "diagnostics in space". We included papers published between January 1970 and September 2025: original research, meta-analyses, systematic reviews, clinical and observational studies, clinical trials, and references cited in selected articles. Case reports were excluded. Key Content and Findings: Since pioneering studies in the 1970s, progress in this field depends on our capacity to develop miniaturized platforms for analytical assays and to implement in situ high-throughput techniques for DNA identification, and for quantifying RNA, polypeptides and other clinically relevant biomarkers. Many of these methods derive from "omics" technologies that have transformed biomedical research in recent decades. Intensive efforts are underway to perform omics. Astronaut health relies on a three-tiered diagnostic framework integrating real-time physiological monitoring, omics-based risk stratification, and targeted clinical testing. The use of wearable biosensors and digital twins further enables personalized countermeasures to maintain optimal performance in extreme space environments. Conclusions: Establishing robust Laboratory Medicine capabilities in space is mandatory to address multiple challenges, including health assessment, development of life-support systems, and the study of biological processes under extreme conditions. These systems require automation, miniaturization and rigorous validation.