The knee is the largest hinged joint in the body and knee problems are common. A 2006 Center for Disease Control and Prevention survey showed that 30 percent of adults reported pain in the previous 30 days, with 18 percent complaining of knee pain and stiffness. Fluid in the knee, or effusion, can be caused by trauma, an overuse injury, or disease, according to MayoClinic.com.
Stop any activity that may have caused the knee to swell, like running, jumping or twisting. Discontinue action that makes your knee swell or hurt. You may have to avoid driving if it causes discomfort to operate the brake or gas pedals.
Rest with the leg elevated to reduce swelling. This allows fluid to drain away, and reduces pressure on the joint. Don't walk or put weight on the knee unnecessarily until the pain and fluid have subsided.
Use a cold pack to alleviate pain and reduce fluid buildup. You can use a wash cloth soaked in cold water, or a commercial cold pack stored in the freezer. Do not use ice or freezer packs directly on the skin; instead, wrap the frozen product in a towel and wrap it around the knee. Apply this cold pack for 15 to 20 minutes every two to four hours as needed for pain.
Wrap the leg with an elastic bandage. This should reduce accumulation of fluid on the knee. Do not wrap the knee so tightly that it cuts off circulation; remove the bandage if numbness or tingling in the foot occurs, or if the foot feels warm.
Take a nonsteroidal anti-inflammatory like ibuprofen or naproxen to decrease or prevent inflammation, MayoClinic.com suggests. Brand name medicines that include NSAIDs can include Advil, Motrin or Aleve. Take them with food to avoid stomach irritation. A pain reliever, such as acetaminophen or Tylenol, can also be used to relieve pain, but will not reduce the inflammation in the knee.
See a doctor if the fluid does not go down in a few days, or if the cause of fluid in the knee cannot be determined. A doctor may choose to aspirate fluid by inserting a needle into the knee and drawing the fluid into a syringe. She will send the fluid to the laboratory, where it will be tested to find out the cause of the fluid buildup. Antibiotics may be prescribed, as well as medicines like corticosteroids to reduce swelling.
Seek medical attention if pain persists, or other symptoms like fever develop as these could be signs of complication such as infection.
Maintain physical therapy appointments as directed by your physician. Physical therapy may help reduce inflammation as well as attend to the underlying cause of fluid on the knee. Therapy will also strengthen the muscles around the knee, giving this important joint more power and stability.