Going to space is harsh on the human body, and as a new study from our research team finds, the brain shifts upward and backward and deforms inside the skull after spaceflight.

The extent of these changes was greater for those who spent longer in space. As NASA plans longer space missions, and space travel expands beyond professional astronauts, these findings will become more relevant.

Why it matters
On Earth, gravity constantly pulls fluids in your body and your brain toward the center of the Earth. In space, that force disappears. Body fluids shift toward the head, which gives astronauts a puffy face. Under normal gravity, the brain, cerebrospinal fluid and surrounding tissues reach a stable balance. In microgravity, that balance changes.