My knee is swollen what do i do?

Rest, ice, compress: RICE = Rest, Ice, Compression, and elevation (at least level/flat-- on couch). This is the first line of self treatment for a swollen knee. If swelling persists past several days , and/or a fever or redness develops, see your physician for a thorough evaluation.

See specialist.: See an orthopedic knee specialist, who could assess your knee. Fluid on the knee is not normal, and the source needs to be determined and treated.

Be seen: If it does not respond to simple things like rest, ice, compression, elevation; I would consider being seen for an accurate diagnosis.