 [ Symptoms ] can a viral infection cause knee problems my boyfriend is knees are stiff and painful his knee caps are ok thnak you [ Disease ] a viral infection should not cause knee pain and stiffness does he have pain in any other joints if not he should see an ortopaedic md and have it looked at he should try to excercise as often as he can by walking he certainly should not try running as running puts a lot of strain on the knees and the joints of the knees his knee caps may look ok but just looking at them is not enough to tell if he has something more serious possibly needing in the future knee replacement he should try taking aleve or some otc medication walk as much as he can and consult his physician