Sound like osteoarthritis (OA) which most often occurs in people over 45, but some younger people get it from a joint injury
. Do you have any previous injury
involving your knee
? A torn cartilage, for example, can precipitate the process of OA. Weight also plays an important role. Do you experience a creaking or cracking feeling within the joint?
In the meantime, bracing, splinting, and other orthotic treatments may be useful in “unloading” an arthritic joint surface.