I'm 20 years old and both of my feet start to turn to a purplish color within 5 minutes of sitting down. They also do this while I'm standing still. The only time this doesnt occur is when I'm laying down or doing something active with my legs. At times my feet get a tingling feeling or start to swell up after they have turned purple. This has been goin on at least since March of this year. I dont smoke and I am pretty active especially during school. I just recently went to the doctor and he had no clue what it was. The only thing he kept askin was if I smoked. He wanted me to take blood pressure medication but I wasnt very comfortable takin some meds for a condition he had no idea about. Does anyone have an idea what this could be??