knees giving out

Both legs have been like this for a while, usually one worse than the other. No pain tho, just aching and strange pressure in what feels like the joint where my fibula meets my knee. Sometimes it runs along the whole bottom line to the patella. I'm only 23, this started minorly when i was 16 and peaked when i was 18, I ran alot and just attributed to excess volume, as every1 on the team had problems of some kind. I quit running for several years and am starting back, and this problem is flaring up again. Before i make the trip to see most likely several doctors, Id like to go in with some idea of whats going on.