Causes of Edema During the Inflammatory Process

Pathophysiology of Inflammatory Edema

Inflammation leads to increased vascular permeability or capillary leak, allowing fluid to move from blood vessels into the interstitial space, according to the American College of Cardiology 1, 2
The increased permeability is mediated by chemical mediators including bradykinin, serotonin, and prostaglandins, as stated by the American College of Cardiology 2, 3
The inflammatory process causes dilatation of the myocardial vascular bed with hyperemia, which contributes to the edema formation, as reported by the American College of Cardiology 1, 4

Inflammatory mediators cause endothelial cells to contract, creating gaps between them that allow fluid and proteins to leak into surrounding tissues, according to the American College of Cardiology 2, 3
The increased vascular permeability leads to a net expansion of the extracellular space, as stated by the American College of Cardiology 2, 4

Bradykinin is a key mediator that increases vascular permeability during inflammation, as reported by the American College of Cardiology 2, 3
Serotonin and prostaglandins also play important roles in mediating the increased permeability, according to the American College of Cardiology 2, 3

The magnitude and spatial extent of edema depend on the severity of the inflammation, as stated by the American College of Cardiology 1, 4