M25.4: Effusion of joint

Effusion of the joint, or joint effusion, is a condition where excess fluid accumulates inside a joint space, causing swelling and discomfort. Several different causes can lead to joint effusion, including trauma or injury, arthritis, infection, and systemic diseases, such as lupus. The most recognized symptom is swelling in the affected joint, but effusion may also cause joint stiffness, pain, and restricted movement. This condition ends up impacting the musculoskeletal system and can affect any joint in the body like the knee, ankle, shoulder, elbow or hip. Depending on the cause, it may affect one joint (monoarticular) or multiple joints (polyarticular). Disease progression varies significantly depending on the underlying cause and may be acute or chronic. Onset is usually gradual, with swelling developing over a period of hours to days. It is important to have all symptoms evaluated by a healthcare provider for appropriate diagnosis and management.