Joint swelling may be caused by different conditions, including:

• Chronic type of arthritis called ankylosing spondylitis
• Painful type of arthritis caused by buildup of uric acid crystals in a joint (gout)
• Arthritis caused by wear and tear of joints (osteoarthritis)
• Arthritis caused by buildup of calcium-type crystals in joints (pseudogout)
• Disorder that involves arthritis and a skin condition called psoriasis (psoriatic arthritis)
• Group of conditions that involve the joints, eyes, and urinary and genital systems (reactive arthritis)
• Inflammation of joints, nearby tissues, and sometimes other organs (rheumatoid arthritis)
• Inflammation of a joint due to an infection (septic arthritis)
• Disorder in which the body’s immune system attacks healthy tissue (systemic lupus erythematosus)

Treatment

The cause of your joint swelling determines its care and treatment. Often once the cause of the swollen joint gets treated, the swelling goes away. However, not all causes of a knee joint effusion are curable. For many, treatment consists of managing your symptoms instead of eliminating them. There are several ways healthcare providers manage your swollen joint. Examples include:

• Antibiotics help with infections. If you have septic arthritis — an infection in your knee joint — your healthcare provider might prescribe antibiotics.
• Arthrocentesis is where your healthcare provider drains the synovial fluid from your swollen joint. They might send it to a lab for testing. Tests could reveal bacteria, proteins, certain blood cells, glucose or other indications of various conditions.
• Colchicine is a medication for people who have gout. It helps with pain, inflammation and joint effusion.
• Steroids help block inflammatory chemicals. Arthritis can cause inflammation, and inflammation can cause joint effusion. Some steroids get swallowed, and others are injected right into your knee joint.

Home Remedies for Joint Swelling

If your joint swells from fluid, there are a few steps you can take yourself. At-home remedies for joint effusion include:

• Heat, especially moist heat, can help with joint effusion and joint pain. People who have arthritis or a swollen joint because of an injury might want to try heat.
• Ice works well on swollen joints. Try it if you have arthritis or an injury.
• Maintaining a healthy weight to reduce stress on your joints.
• Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil®, Motrin®) and naproxen (Aleve®). NSAIDs help treat the swollen joint of people who are injured or have arthritis.
• Resting your joint effusion might help it heal. Try taking weight off your joint by raising it and use a mobility aid like a cane.