I had some mild pain when I ran today. I had to stop after 8 minutes. My left knee felt numb and was unable to bear a lot of weight. I was able to walk fine, I have complete range of motion, and there is no swelling whatsoever.
When I lie down and stretch my knee out in to the air, I hear/feel a faint click around the patella area. This doesn't happen with my left knee.
I'm 20 and have no prior experience with a major injury or surgery. Last year I intentionally lost a bit of weight while running, I haven't run in about 4 months before today because I was focusing on my final examinations .
What's wrong with my knee? There's no pain when I walk, there's complete range of motion. Just a click sound and a weak knee that is unable to bear heavy loads of weight.