exudating

Exudating is the biological process by which fluids, proteins, and cells escape from vessels or tissues, often into surrounding spaces or onto surfaces. It is most commonly discussed in the context of inflammation, tissue injury, or wound healing, but can also occur in plants where sap or other substances seep from damaged tissues.

In human medicine, exudation produces exudates that can collect in cavities or on surfaces. Exudates are typically classified by content: serous (clear or pale yellow, primarily fluid with few cells), fibrinous (high fibrin content), purulent (pus, rich in neutrophils and microbes), and hemorrhagic (significant red blood cells). The driving mechanism is increased vascular permeability mediated by inflammatory signals such as histamine, bradykinin, and cytokines. The composition and volume of an exudate reflect the underlying process, such as infection, autoimmune inflammation, or tissue necrosis. Exudate is distinguished from transudate, which results from altered hydrostatic or oncotic pressures and has a lower protein content and cellularity.

Botanically and in plant physiology, exudating refers to the release of substances such as latex, resin, gums, or enzymes from damaged or specialized tissues. Plant exudates can serve defensive roles or be part of normal secretory processes and may influence interactions with pathogens, herbivores, or soil microbes.

Clinical relevance includes diagnostic insights from exudate appearance and analysis, assessment of wound status, and guiding management such as treatment of infection, drainage, or wound care.