I have been shooting up heroine the past week and. I was on a 6hr plane ride and now my ankles and feet are extremely swollen. What would cause this?

Heroin&swollen feet. Probably NOT a good thing using heroin and flying. Are your "works" clean and used once or are you sharing/using dirty works? Is the swelling on both sides and does it improve over the night (better in AM??) any shortness of breath if not - please get checked. The heroin use may have caused issues with your heart valves. You need to see a doctor and be honest with them. Good luck.