Knee swelling is when more fluid than usual gathers in or near the joints in your knee. It can come on suddenly after an injury, or it can build up slowly over time. The knee is the largest joint in the body. It is also the most injured, which makes swelling a very common problem.

Causes are usually injuries and health conditions such as infections or arthritis. Most of the time, knee swelling is treated with medications or at home care. Sometimes, physical therapy or surgery is needed. Baptist Health orthopedic providers can help you figure out what is causing your knee swelling and create the right plan to treat it.

Signs and Symptoms

Knee swelling is often noticeable as puffy or bloated areas of your knee. Comparing one knee to the other can make the difference easier to see. You might also experience other symptoms.

Common signs include:

• Pain
• Swelling
• Redness
• Warmth
• Stiffness

The warm sensation or reddish coloring is usually a sign of an infection. You may also find that it is hard to fully bend or straighten your leg when extra fluid is in the joint. Some people notice their knee feels tight or heavy before they see any clear swelling.

Diagnosis

Your orthopedic care provider will diagnose you using imaging tests and a physical examination. They will also ask about your symptoms, any recent injuries and your medical history. This gives them a clearer picture of what might be going on.

Imaging tests might include:

• X Rays. X Rays can show broken bones and signs of arthritis.
• MRIs. MRIs give a more detailed look at soft tissues like ligaments and cartilage.
• Ultrasounds. Ultrasounds can help check for fluid and guide certain procedures.

In some cases, your provider will perform a joint aspiration. This is where fluid is drained from your knee. A joint aspiration relieves pressure on your knee or knee joints. Your provider will then test the fluid to learn more about your specific condition. The fluid can show signs of infection, gout crystals or bleeding from an injury.

Causes

There are two main causes of knee swelling and pain: traumatic causes and non-traumatic causes.

Traumatic Causes

Traumatic causes involve tears, injuries, sprains or broken bones. This can mean ACL tears, meniscus tears or fractured knee joints. You might get these injuries from playing intense sports, falling down on your knee or another type of accident that involves your knee. Sports with sudden stops, jumps or twisting movements put you at higher risk. Swelling that shows up right after an injury often means there is bleeding inside the joint, which should be checked by a provider.

Non-Traumatic Causes

Non traumatic causes of knee swelling might be infections or medical conditions. Your provider will look for signs of osteoarthritis, rheumatoid arthritis, bursitis, gout or cysts. A Baker's cyst, which is a pocket of fluid behind the knee, is another common cause. Overuse from repeated activity can also lead to swelling that builds up slowly over time.

Risk Factors

You are more at risk for knee swelling if you engage in intense physical activity such as playing sports. Having a health condition that affects the knee can also make you more likely to experience a swollen knee or knee joint. Extra body weight puts added stress on the joint and can also raise your risk. Age is another factor, since the knee naturally wears down over time. Past knee injuries and weak muscles around the joint can also make swelling more likely.

Treatment

Your orthopedic care provider will usually treat knee swelling with a combination of at home care recommendations and medication. However, sometimes physical therapy or surgery is also necessary.

Treatment includes:

• At home care. At home care may initially follow the RICE method, which stands for rest, ice, compression and elevation, for the first 24 to 48 hours. Your provider will also likely recommend some form of movement and light exercise.
• Medication. Over the counter pain relievers can help reduce pain and swelling. Your provider may also prescribe stronger medication if needed.
• Physical therapy. This helps support your recovery through stretches, body movements and other treatment activities.
• Surgery. If your knee injury is severe, you might undergo knee repair or knee replacement as part of your treatment.

It is also possible that you might need a brace or crutches to support healing and recovery. Your Baptist Health provider will design a treatment plan tailored to your individual condition, lifestyle and general health.

Recovery

Recovery can take from a few days to several weeks or longer, depending on the severity and cause of your knee swelling. If your condition is based on an infection, recovery is typically shorter than if the cause is an injured or broken bone. However, most people make a full recovery from knee swelling.

To prevent swelling in the future, consider these guidelines:

• Avoid strenuous physical movement if you feel pain in your knees.
• Use proper form when lifting weights.
• Use the recommended protective equipment when playing sports.
• Allow time for stretching before physical exercise.
• Give yourself time to stretch after physical exercise.
• Keep the muscles around your knees strong with regular exercise.
• Maintain a healthy weight to reduce stress on your joints.

If you cannot put weight on your leg, are in severe pain or develop a fever along with swollen knees, please seek medical care immediately. These can be signs of serious health problems. You should also see a provider if at home care does not improve your symptoms after a few days, or if the swelling keeps coming back.