An effusion means excess fluid has collected in a body space, such as around the lung, heart, or in a joint.
Symptoms depend on where the fluid is. Some effusions cause pain, swelling, stiffness, breathlessness, or pressure symptoms, while others are found incidentally.
Imaging helps confirm that fluid is present, show where it has collected, estimate how much there is, and guide drainage if needed.
X-ray, ultrasound, CT, and MRI can show where the fluid is and help estimate how much is present.
Care depends on the cause and may include observation, medicines, drainage, or treating the underlying disease.
This entry explains the finding. The next step is having a radiologist interpret your specific scan, not a general definition.
