One astronaut's case shows how space travel could lead to rare blood clots

In a new NEJM letter to the editor, scientists describe how an astronaut developed a blood clot while aboard the International Space Station, revealing how space travel can disrupt blood flow and cause complications. The clot — in the astronaut’s jugular vein and a form of deep vein thrombosis — was discovered during a routine checkup and was initially treated using a blood thinner that was in the ISS’s medical kit. Several space and medical agencies worked together to dispatch another type of blood thinner to the space station that the astronaut then took. Upon his return to Earth, however, the blood clot seemed to have gone away. Such clots are usually not associated with space travel, and the case illustrates there’s still much to be learned about space medicine before space travel becomes more routine, the authors write.