stiff, swollen, and painful after driving a couple of hours. I'd had the same thing for my entire life but no one could tell me why. After 40 years I was finally diagnosed with an Arteriovenous malformation (AVM). It was only diagnosed after having an MRI with contrast and they saw the blood flow to my hip was a crazy mess. I had veins without the valves that prevent back flow so the blood would pool up and cause all the problems. Found a doctor in Colorado that had pioneered a method of getting rid of the bad veins. Took several treatments but solved my problem.