The author of a small study posits that fluid can move from the legs into the neck, restricting the flow of oxygen to cause sleep apnea, reports Reuters Health.

“Getting rid of excess fluid is one approach of treating sleep apnea,” said Bradley, a sleep specialist and professor at the University of Toronto.

Compression stockings, widely used to treat varicose veins and by workers whose jobs keep them on their feet all day, exert pressure on the legs and reduce fluid movement.

“This study highlights what we believe to be a new cause of sleep apnea,” Bradley said. “This is further evidence that it really is a mechanism that causes sleep apnea.”