Talk to Rheumatologist on Permenant Pain In Left Leg And Now In Knee (with Swelling)

My mother is facing pain in her leg for a long time. While she is walking and working, it doesnt irritate, but when she lay down for rest , it starts paining. Recently, swelling has developed in her knee along with more pain (could be a new thing, not sure)

visited many doctors and they only prescribed painkillers for leg pain. For knee issue, she is using brufen for swelling and pain