Hello
As lyser advised and you got relief till medicine , you took.
Yes this is a pain killer .
Pain around the knee in leg may be due to these possibilities , these include :
1
Osteoarthritis , as this is a common cause of such swelling and infection is the main cause .
Diagnosis can be confirmed by C T Scan of the part.
2
Osteoporosis may be the another reason of such symptoms . Diagnosis can be confirmed blood examination for calcium ,
bone density level and D3 level.
3
Blunt injury is another most common cause due to imbalance of movement of knee , hence swelling develop.
However ,there are so many other causes like local cellulitis etc.
In my opinion consult an ORTHOPEDIC surgeon and get his opinion as physical examination is also important .
Some times fluid ( known as
synovial fluid also accumulated in the joint).
Good luck.