Which condition is characterized by the presence of fluid in a cavity?

Effusion is the condition characterized by the presence of fluid in a cavity. This fluid accumulation can occur in various body cavities, such as the pleural space around the lungs, the pericardial cavity surrounding the heart, or within joints. The fluid can come from various sources, including inflammation, infection, or injury, leading to symptoms depending on the location and extent of the effusion.

Understanding the specifics of effusion is essential, especially in medical contexts, as it can indicate underlying pathologies that require attention. This condition often necessitates further investigation through imaging or fluid analysis to determine the cause and appropriate treatment.

The other options, although they represent important medical terms, do not describe the accumulation of fluid in a cavity. For instance, embolism pertains to a blockage of blood vessels, dysphagia refers to difficulty swallowing, and dyspnea describes shortness of breath. These terms are clinically relevant but do not share the defining characteristic of fluid presence in a cavity.