A joint effusion means extra fluid has built up inside a joint space.
Common symptoms include joint swelling, stiffness, pain, reduced movement, and a feeling of pressure inside the joint.
Imaging helps confirm the fluid, look for arthritis, injury, infection, or inflammation, and guide aspiration when needed.
Ultrasound, X-ray, or MRI may help show the fluid and whether arthritis, injury, or infection is contributing.
Treatment depends on the cause and may include observation, aspiration, medicines, or orthopedic or rheumatology care.
This entry explains the finding. The next step is having a radiologist interpret your specific scan, not a general definition.
