font size

Superior Vena Cava Syndrome (cont.)

Medical Author:
Medical Editor:


The superior vena cava is a large vein located in the upper chest, which collects blood from the head and arms and delivers it back to the right atrium of the heart. If this vein is compressed by outside structures, or if a thrombus or clot develops within it, return blood flow to the heart is impeded. When blood flow to the heart is restricted, the increased pressure in the veins of the face and arms causes edema (fluid buildup) in these areas. This condition is referred to as superior vena cava syndrome.

Because the superior vena cava, like all veins, has a thin wall (there are no muscles in the walls of a vein as compared to the walls of an artery), and because there is little pressure inside the vein, it can be easily compressed by outside structures. The superior vena cava lies next to the upper lobe of the right lung and within the mediastinum [the space that contains the central structures of the chest: the heart, the trachea, the esophagus and the great vessels (aorta, vena cava)]. Abnormalities within any of these structures can cause the compression.

What causes superior vena cava syndrome?

The most common cause of superior vena cava syndrome is cancer. Primary or metastatic cancer in the upper lobe of the right lung can compress the superior vena cava. Lymphoma or other tumors located in the mediastinum can also cause compression of the superior vena cava.

Less often, the superior vena cava can become blocked with a blood clot from within. As more invasive medical procedures are being performed on patients, this cause of superior vena cava syndrome is being seen more frequently. Blood clot (thrombus) formation that causes superior vena cava syndrome is a complication of pacemaker wires,dialysis, and other intravenous catheters that are threaded into the superior vena cava.

Historically, and in other parts of the world, infection (syphilis and tuberculosis) is another cause of superior vena cava syndrome. Sarcoidosis (a disease that results in masses of inflamed tissue) may also cause this syndrome.

Medically Reviewed by a Doctor on 1/22/2014

Patient Comments

Viewers share their comments

Superior Vena Cava Syndrome - Symptoms Question: What were the symptoms experienced with superior vena cava syndrome in you or a relative?
Superior Vena Cava Syndrome - Treatment Question: What kinds of treatment, including medication, have you or a relative received for superior vena cava syndrome?


Get the latest treatment options.

Use Pill Finder Find it Now See Interactions

Pill Identifier on RxList

  • quick, easy,
    pill identification

Find a Local Pharmacy

  • including 24 hour, pharmacies

Interaction Checker

  • Check potential drug interactions
Search the Medical Dictionary for Health Definitions & Medical Abbreviations