Congestion

Overview
  • Congestion is a localized increase of blood in a particular tissue due to poor venous outflow. Consequently, congestion is almost always due to some circulatory pathology in veins downstream of the congested area.
Pathogenesis
  • Overview
    • The short-term consequences of congestion largely cause derangements of fluid handling. Over time, however, chronic congestion can induce major morphological changes in affected organs.
  • Acute Sequelae
    • Poor venous outflow results in increased intravascular pressure in venules that modify the Starling Forces of fluid exchange between the interstitial fluid and blood. The consequence is increased filtration of fluid out of the vasculature, thus causing localized edema.
  • Chronic Sequelae
    • Poor venous return ultimately results in reduced blood flow to the affected tissues and if occurring over long time-scales results in ischemia to the affected capillaries and surrounding parenchyma. Injured capillaries become significantly leaky and ultimately small, focal hemorrhages result. Over the long-term significant injury can result to the tissue and wound healing processes can ultimately cause significant tissue remodeling.