Obstruction of the caval vessels, usually due to a tumor.
- Depending on the location (superior or inferior), will be seen as marked dilation of the vessels in the half of the vessel, cyanosis, and edema
- Superior Vena Cava syndrome will be seen in the upper half of the body
- Inferior Vena Cava syndrome will be seen in the lower half of the body and is often associated with vascular liver