Superior Vena Cava Syndrome

Medically Reviewed by Sabrina Felson, MD on November 11, 2022
Written by Paul Frysh
3 min read

Superior vena cava syndrome (SVCS) is when something -- usually a cancerous tumor -- blocks or pinches the superior vena cava, a major vein that carries blood from your chest, neck, and head to your heart.

One sign of superior vena cava syndrome is swelling in your face, arms, neck, head, or upper body. It may get worse when you bend forward or lie down. You might start to cough or have trouble breathing.

Less common symptoms include:

Cancer is the primary cause of superior vena cava syndrome, most typically:

  • Lung cancer
  • Non-Hodgkin's lymphoma
  • Cancers that spread to your chest

Less common cancers that could cause superior vena cava syndrome include:

There are a number of common ways that cancer causes superior vena cava syndrome:

  • A tumor in the chest could push on the superior vena cava vein.
  • A tumor might grow into the vein and block it.
  • Lymph nodes near the vein may start to swell or enlarge because of cancer, and so pinch or push on it.
  • Cancer can cause a blood clot in the superior vena cava.

Noncancerous conditions that can cause superior vena cava syndrome include:

  • Blood clots resulting from problems with a pacemaker or a catheter (a flexible tube that goes into a vein)
  • Mediastinal fibrosis: Scarring in the area between your lungs
  • Blood vessel diseases like aneurysms, vasculitis, or arteriovenous fistulas
  • Infections such as tuberculosis, syphilis, or histoplasmosis
  • Noncancerous tumors including dermoid cysts, teratomas, and thymomas
  • Pericarditis: Inflammation of the sac around your heart

Your doctor will do a series of imaging tests that take pictures of your insides to try and figure out if you have SVCS. These include:

The doctor may use a special X-ray process called venography. They’ll inject a dye into your vein before they take the image. This provides more detail about the type and location of the blockage in your vein.

In many cases, SVCS could be an early sign of cancer. Tests that could help your doctor diagnose cancer include:

  • Sputum cytology: Collecting and analyzing of mucus from your lungs
  • Biopsy: Removing of tiny bit of a lymph node or tumor to check it for cancer
  • Bronchoscopy: Using a camera on a tube that goes down your throat to look inside your lungs
  • Thoracotomy: Surgery to examine or make repairs inside your chest

Treatment depends in large part on what’s causing your superior vena cava syndrome. If your symptoms are mild and the underlying cause isn’t serious, you may not need treatment right away.

Often SVCS improves as a side effect of cancer treatment such as chemotherapy or radiation. For example, as the tumor gets smaller, it may push less on the superior vena cava.

Other treatments might include:

  • Corticosteroids to lessen swelling
  • Diuretic medications that get rid of extra fluid
  • Thrombolysis to break up a blood clot in the vein
  • Opening up the vein to help blood flow with tube-like “stent”
  • Surgery to bypass the blockage