Ask the doctor: Compression stockings for a long-distance flight?

Q. My 61-year-old mother plans to take a long plane trip. Her legs usually become swollen when she flies a long distance. Should she wear elastic stockings or take any other precautions so she doesn't develop a blood clot in her legs?

A. Developing mild swelling in the feet, ankles, and lower legs is common during long-haul flights. Sitting still is the culprit — blood and fluid pool in the lower extremities because they aren't aided in their return to the heart by contractions of the leg muscles. When the swelling occurs in both legs, it is benign, though annoying (especially when it is difficult to put your shoes back on at the end of the flight). Swelling in one leg, however, may be worth further evaluation.