Category: Space > Physiology
When astronauts spend even just a day in the microgravity environment of space, their bodies begin to experience significant physiological changes. One of the most notable effects is the redistribution of bodily fluids. In microgravity, fluids that would typically settle in the lower extremities shift toward the upper body and head, resulting in a puffy appearance of the face and increased intracranial pressure. This fluid shift can also affect eyesight, leading to vision problems for some astronauts. Additionally, muscles and bones start to weaken due to the lack of gravitational stress, which can begin to happen within just 24 hours. To counteract these effects, astronauts engage in regular exercise aboard the International Space Station, employing specialized equipment to help maintain muscle strength and bone density during their missions.