Left knee pain coming back after 3 years of injury

[Msinha10]

I fell on my knee 3 years ago , got a cut mark , eventually it healed , no fracture or ligament injury that time as I tested. Now still if I try to do some exercise which puts pressure on my left knee it get swelled , i don't what makes the pain come back, will it not get recovered fully ever?

[Paxiled]

It sounds like you might have suffered an injury your doctors didn't discover, such as a torn meniscus.  Sometimes our bodies are just odd about stuff like this, they just get hurt and stay hurt and nobody can figure out why, but that's also most often in old people.  But without new diagnostic tests, especially MRIs, and having a good orthopedist manipulate your knee to see if certain movements cause pain, you'll really never know.