After a swollen knee: 1. The lower extremity in question should avoid weight bearing, give proper rest, elevate the affected extremity in bed, and give a cold compress of an appropriate ice water mixture to the knee. If there is no relief within a short period of time, you should go to the hospital and undergo relevant examinations, such as X-ray, CT and, if necessary, MRI of the knee, rheumatoid factor, blood sedimentation, C-reactive protein and routine blood tests. 2. If the pain is severe, you can take oral ibuprofen or Celecoxib capsules If the pain is severe, you can take oral ibuprofen or celecoxib capsules for anti-inflammatory and analgesic purposes, and then do further treatment according to the auxiliary examination results and medical history. The above health science knowledge is for reference only, the specific must go to the regular hospital in time, under the guidance of professional physicians for further diagnosis and guidance treatment.