Knee pain can occur for many reasons, whether it was because you overworked yourself, or you have a genetic predisposition. You can do something about it and eliminate the discomfort if you are conscious of certain pain-relieving measures.
It may sound counterintuitive, but sometimes the best way to reduce swelling in your knee is to exercise. Do mild exercises that help stretch out the leg muscles. Strength training is particularly great to do because it helps build up the muscles that surround your knee joint.
With some exercise and a little getting used to, you can then gradually manage to put more pressure on your joints throughout the day. Cardiovascular exercises on an elliptical can also help you build up leg strength and pain tolerance.