What is passive congestion?

2 types Loco-regional (venous): any obstruction of blood flow through a vein, by blockage, stenosis, compression, valvular insufficiency (vein occlusion by thrombus of leg/ varicose vein due to valvular insufficiency/ anoxia of endothelium due to increased venous pressure leading to edema (transudate), collagen sclerosis of venous walls, damage of adjacent tissue (varicose ulcers) Passive Cardiac congestion: obstruction preventing venous return to heart, due to heart failure, birth defects, valvular diseases, myopathies, leads to increase in venous blood pressure in large/small circulation causing venous dilation and decreased blood flow, tissues suffer from hypoxia produce edema, and organs get cyanosis and increased weight