label: Superior Vena Cava Syndrome
label_lc: superior vena cava syndrome
description: Obstruction of the blood flow in the superior vena cava caused by a malignant neoplasm, thrombosis, or aneurysm. It is a medical emergency requiring immediate treatment. Signs and symptoms include swelling and cyanosis of the face, neck, and upper arms, cough, orthopnea, and headache.