effusion
Meaning of effusion: An effusion is an abnormal buildup of fluid in a body space or between tissue layers, named for the specific location involved, such as pleural or joint.
Definition of effusion
An effusion is an abnormal accumulation of fluid within a hollow space or between two layers of tissue that would not normally contain more than a minimal amount of fluid. The term is generally paired with a location to specify where the fluid has collected.
A pleural effusion, for example, is a buildup of fluid between the two layers of membrane surrounding the lung, while a pericardial effusion collects around the heart and a joint effusion collects within a joint space. Each type can arise from a different range of underlying causes, including infection, inflammation, heart or liver disease, or injury.
Depending on its size and location, an effusion can be a minor finding discovered incidentally on imaging or can produce noticeable symptoms, such as breathlessness with a large pleural effusion or swelling and reduced motion with a joint effusion, and evaluating an effusion typically includes identifying the underlying condition responsible for the fluid buildup.
Used in a sentence
Imaging identified a pleural effusion that was later drained to relieve the patient's breathlessness.
Good to know
The word effusion always requires a location to be meaningful, since a pleural effusion, a pericardial effusion, and a joint effusion involve entirely different body spaces and different underlying causes.
Word origin
Where “effusion” comes from
Formed from Latin effundere, meaning to pour out, from ex-, meaning out, and fundere, meaning to pour.