For as long as I can remember, my left knee has had a lump on one side, very bony and hard. It's not soft or movable at all and doesn't change size. For the longest time it felt like just part of my knee (like that bony part on the outer side of the knee, but bigger) but for a few years it has been really sensitive. For example if I accidentally bumped it, it would hurt pretty bad. Pressing my fingers down on it doesn't reveal any softness but it still hurts like I'm pressing on a bruise.
It's pretty large and noticeable now. I went to the doctor a few years ago and he measured my flexibility and whatnot (I can still bend that leg as much as I can bend the other one) and he said my left knee definitely looked significantly different from my right knee. Yet when they took X-rays they apparently didn't see anything? I never got to look at the X-rays or discuss them with the doctor, they just called my house and informed my mom that they didn't find anything unusual. I was a minor at the time so I wasn't getting much information.
Lately it's been hurting more and instead of just hurting when bumped or when pressure is applied, it sometimes aches of its own accord (not very often) and own rare occasions there is pretty sudden pain. When this happens it is very painful to walk. I haven't been to the doctor for a multitude of reasons but plan on making appointments with more than a few so I can make sure to get this resolved. I would just like to know possibilities for what it could be so I can know what to expect, know what tests and things to ask for, and know what kind of doctor to go to if the general physician "doesn't find anything".