I'm just starting out diving and during class last weekend my instructor told us a story. He'd been diving for a few days and waited about 17 hours before flying home. Well, on that flight his fingers and forearms went completely numb. After he landed (fingers/arms felt better once he was on the ground) he called a doctor friend of his who said that yeah, he was bent. Now, my instructor waits about 30 hours before flying after doing multi-day dives, which means no dives at all the day before his flight home.