SVC obstruction

Alternative Names

Superior vena cava obstruction; Superior vena cava syndrome

Definition of SVC obstruction

SVC obstruction is a narrowing or blockage of the superior vena cava — the second largest vein in the human body. The superior vena cava moves blood from the upper half of the body to the heart.

Causes, incidence, and risk factors

Superior vena cava (SVC) obstruction is a relatively rare condition.


Symptoms occur when something blocks the blood flowing back to the heart. They may begin suddenly or gradually, and may worsen when bending over or lying down.

Signs and tests

An examination may show enlarged veins of the face, neck, and upper chest. is often high in the arms and low in the legs.


The goal of treatment is to relieve the obstruction.

Expectations (prognosis)

The outcome varies depending on the cause and the extent of obstruction.


Jacob L. Heller, MD, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington, Clinic. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 1/16/2009

Heart, section through the middle

ADAM Medical Encyclopedia

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