I also experience from this reoccuring water on the knee. The three doctors I've gone to don't seem to know what causes it. It doesn't hurt at all. I have had several cortisone injections. They seemed to work, but a few months later (two weeks ago) it filled up again. Getting it drained didn't work. It filled up again just a few days later every time. Cortisone seems to work, but I am 14 and I am worried about the risks. Although, at this point, I'm happy with whatever works because I'm just trying to get back to running and playing soccer.
I got a large splinter in the bottom of my right knee about 6 weeks ago. My knee was very sore and swollen for about 4 days. Then the swelling went down. About 3 weeks ago the top right side of my knee started to swell. There is a large pocket of fluid underneath the skin. I went to the doctor and he drained the fluid out with a needle. The tests on the fluid were negative for infection. The doctor told me to wrap the knee so the fluid would not come back. This did not work. Again my knee is filled with fluid. There is no pain just a little tenderness when I kneel. I have 2 kids in diapers and I am on my knees alot. That is the only time I notice it and sometimes it seems to feel like a balloon about to burst. I have been searching for an answer online and it seems that there is many people with unexplained water on the knee. Let me know if you find out what is causing yours.
My left knee began to swell about 4 days ago. There's fluid around my entire knee front and back. There is also a fairly large pocket of fluid at the top left of my knee. However, I am in no pain but there's stiffness. I have not gone to see a doctor because I wanted to see if ice or heat would reduce the swelling. The swelling has reduced some but not completely and the tightness still exist. I played collegiate and professional women's basketball. I played with pain and swelling my entire career. However, I have not played for many years and have not had any problems with my knee until recently. The only thing I've done that could have caused the swelling was carry heavy trash bags up and down stairs last week. Could this be water or something else?