Question

Astronauts get facial edema when in space and for a short time upon return to Earth. What causes facial edema and what is its relation to capillaries? Does plasma transfer across capillaries and is edema plasma buildup in the tissues? Some clarification please.

Answer 1

Space is a strange place to live as there is no gravity present over there. In space, astronauts lose fluid volumeand due to this they have less blood to pump, which will eventually cause the atrophy of the heart. Under the effects of the earth's gravity, blood and other body fluids are pulled towards the lower body. When gravity is taken away or reduced during space exploration, the blood tends to collect in the upper body instead, resulting in facial edema and other unwelcome side effects.