Pain and swelling can be because of plenty of reasons. Needs to be evaluated
a) it can be inflammatory like gout (uric acid) or seronegative arthritis
b) it can be degenerative like osteoarthritis
c) it can be traumatic
Do ice fomentation
Don't bend Ur knee much
Need few blood test like uric acid levels , ESR, CRP, XRay of knee (AP,lateral)
Disclaimer : The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding your medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.