So, I'm 31 and have never had any major health problems and am not overweight. I have had a few instances where the upper part of my legs are in a great deal of pain, they get to a burning feeling, and I'm barely able to walk or sit down or get up off a chair. (This has happened like three times in the last few years and lasts about 1-2 weeks). Daily though, my pain is dull throughout the entire day but does not affect anything major but seems to be getting more consistent. It kills my legs to climb more than 4-5 steps and if I lay down on either side, the leg on top has a painful burning feeling continuously. I flip over all night and it only eases up if I switch to my back. I've tried elevating my legs, putting a pillow between them, stretching them out a nothing works. What could be going on?