Superior vena cava syndrome (SVCS) occurs when blood flow through the superior vena cava, the large vein that carries blood from the upper body to the heart, is blocked or compressed, according to Cleveland Clinic. This can lead to swelling of the face, neck, and upper body, as well as other symptoms like shortness of breath and cough, notes the Canadian Cancer Society. 

Causes:

• Cancer:The most common cause of SVCS, particularly lung cancer and non-Hodgkin’s lymphoma, states Healthline. Tumors can compress or grow into the SVC, according to Loma Linda University Children’s Hospital.Â
• Infections:Rare causes include infections of the mediastinum (the space in the chest) that can cause thickening and hardening of tissues, explains Loma Linda University Children’s Hospital.Â
• Blood clots:Blood clots can form in the SVC, particularly in patients with central venous catheters or pacemaker wires, says the Cleveland Clinic.Â
• Other causes:Less common causes include germ cell tumors, metastatic breast cancer, and sarcoidosis, mentions Loma Linda University Children’s Hospital.Â

Symptoms:

• Swelling of the face, neck, upper body, and arms.
• Shortness of breath.
• Cough.
• Bluish discoloration of the skin, especially around the face and chest.
• Distended veins in the chest and neck.
• Headache.
• Difficulty swallowing.Â