"I noticed the swelling in my leg and it started to turn a little blue. That told me that something was wrong and obviously not enough circulation," Wylie said.
Angered that American Airlines never informed him of the potential risk of what's commonly called economy class syndrome, Wylie has joined a growing number of disgruntled passengers suing airlines.
"I think the fact airline industry not acknowledging long distance airline travel and blood clots is frustrating. It is preventable. I think I could have prevented it,'' said Wylie.
Wylie's lawsuit against American Airlines could be the first of its kind to make it to trial in the U.S. He claims that the airline knew the seating configuration and conditions, like the pressurized cabin and extremely dry air on the plane could cause the dangerous clots.
"A blood clot can break free and travel to your lungs, and in some cases that can be fatal," says Dr. Vincent Rowe, a vascular surgeon at the University of Southern California.
Although a February 2001 memo from the International Air Transport Association warns that "travelers should be informed of the risks of dvt," most airlines don't mention it.
American Airlines would not talk about the claims. But if Wylie's case goes to trial, it could pose a huge financial nightmare for all airlines. The Airline Trade Association denies a link.
"In our view there is no connection between DVT and airline travel," said David Berg, with the association.
Some airlines advise passengers to stretch or do mini-exercises. But critics say the only way to really decrease the risk of blood clotting is to get up every hour and walk around.
Try doing that on a plane with a 17-inch aisle and drink service already in progress.