【英文原文】
Sleeping tight could be bad for your kidneys
Good news for restless sleepers --researchers at the University of California tell us that kidney stones could be caused by sleeping too long in one position.Over 75percent of people with recurrent kidney stones who always slept on one side got stones on that side of the body.This led the researchers to suggest that if the person stays in one position,the blood flow can become sluggish and stones(made from substances including calcium) and magnesium may then form.