Risks of Decompression Sickness and Venous Thromboembolism during Spaceflight and Patent Foramen Ovale Implications

In August 2026, NASA’s Office of the Chief Health and Medical Officer established a working group focused on critical health risks associated with future spaceflights. This initiative specifically examined recent data concerning extravehicular activity prebreathe testing, decompression sickness events, and venous thromboembolism incidents during flight operations. The working group's analysis also considered the implications of patent foramen ovale in relation to NASA’s Artemis program, which aims at lunar and deep-space exploration. These recommendations are based upon prior efforts led by the OCHMO. The goal is to enhance astronaut safety throughout all phases of these ambitious missions.