Superior Vena Cava (SVC) Syndrome

Author: Marisa Healy, BSN RN
Content Contributor: Katherine Okonak, LSW
Last Reviewed: May 09, 2024

What is superior vena cava syndrome (SVC)?

The superior vena cava (SVC) is a large blood vessel that carries blood from your head and upper body to your heart. SVC syndrome happens when blood flow through the superior vena cava is blocked.

SVC syndrome is an oncologic emergency, which is a serious health problem caused by the cancer itself or its treatment. Oncologic emergencies need to be treated right away.

What causes SVC syndrome?

SVC syndrome is often caused by a tumor or enlarged lymph nodes pressing on the SVC. SVC syndrome is common in lung cancer, lymphoma, breast cancers, and with other primary tumors that have spread to the chest. It can also be caused by blood clots within the SVC.

What are the symptoms of SVC syndrome?

Symptoms can happen slowly or quickly. If SVC syndrome is caused by cancer, then symptoms often happen more slowly than if it is caused by blood clots. Symptoms can be:

  • Swelling of the face, arms, or upper chest.
  • Having a hard time breathing (dyspnea).
  • Widening of the veins in the neck and chest.
  • Cough and/or coughing up blood (hemoptysis).
  • Headache or a feeling of fullness in the head and ears.
  • Having a hard time swallowing (dysphagia).
  • A hoarse or strained voice.
  • Chest pain.
  • Blue or red-coloring to the skin of the face or upper body.
  • Changes to your vision.

How is it diagnosed and treated?

SVC syndrome is an oncologic emergency and needs to be treated right away. It can be diagnosed through a physical exam and chest x-ray, but you may need imaging tests (CT/MRI/venography) to measure how much of the SVC is blocked.

SVC syndrome is treated based on the cause:

  • If SVC syndrome is caused by a tumor pressing on the SVC, chemotherapy or radiation therapy may be used to shrink the tumor. This helps the blood flow better. A stent may be put in the SVC to hold it open to allow blood flow.
  • If a blood clot is causing SVC syndrome, blood thinners will be given.
  • Corticosteroids can be used to lessen swelling.
  • Diuretics may be used to decrease the amount of fluid in the body.

When should I call my care team?

If you are having any symptoms of SVC syndrome listed above, call your care team right away. If you are having a hard time breathing, call 911 or go to the emergency room right away.

American Society of Clinical Oncology (ASCO). Superior Vena Cava Syndrome. 2020.  

Azizi A, Shafi I, Shah N, et al. Superior Vena Cava Syndrome. J Am Coll Cardiol Intv. 2020 Dec, 13 (24) 2896–2910.

Canadian Cancer Society. Superior Vena Cava Syndrome. 2024.

Seligson, M.T. & Surowiec, S.M.. Superior Vena Cava Syndrome. 2022.