When astronauts return to Earth, their altitude isn't the only
thing that drops—their blood pressure does too. This condition,
known as orthostatic hypotension, occurs in up to half of those
astronauts on short-term missions (two weeks or less) and in
nearly all astronauts after long-term missions (four to six
months). A new research report published online in The FASEB
Journal solves the biological mystery of how this happens by
showing that low gravity compromises the ability of arteries and
veins to constrict normally, inhibiting the proper flow of
blood. Prevention and treatment strategies developed for
astronauts may also hold promise for elderly populations on
Earth who experience orthostatic hypotension more than any other
age group. "The idea of space exploration has been tantalizing
the imagination of humans since our early existence. As a
scientist, I have had the opportunity to learn that there are
many medical challenges associated with travel in a weightless
environment, such as orthostatic hypot