decreased capillary oncotic pressure
loss or diminished production of plasma albumin contributes to a a decrease in plasma oncotic pressure. decreased oncotic attraction of fluid within the capillary causes fluid to move into the interstitial space. decreased production of plasma protein may occur with liver disease or protein malnutrition. losses of plasma proteins occur with glomerular diseases of the kidney, serous drainage from open wounds, hemorrhage, burns, and cirrhosis of the liver.
increased capillary permeability
is usually associated with inflammation and the immune response. often a result of trauma, protein escapes from the plasma and produces edema through a loss of capillary oncotic pressure and gain in interstitial fluid proteins.
increased capillary hydrostatic pressure
results from venous obstruction or salt and water retention. hydrostatic pressure of fluid within the capillaries is increased enough to cause fluid to escape into the interstitial spaces.
lymphatic obstruction by inflammation or tumors can cause edema.