Superior vena cava syndrome refers to the disease of impaired blood return in superior vena cava system due to various reasons, and its main manifestation is the symptom of upper body bruise, such as bruise and edema in head, face and neck. 1. Etiological factors: the more common ones are neoplastic diseases, such as lung cancer, mediastinal tumor, esophageal cancer, etc., which cause compression to the superior vena cava vessels and then cause obstruction to the blood return of the superior vena cava system; non-neoplastic factors include thrombosis in the superior vena cava, mediastinitis and pericardial effusion. 2. Clinical manifestations: Due to the obstruction of blood return of superior vena cava system, patients may manifest vascular dilatation and congestion in the head, face, neck, upper limbs and other parts of the body, which may even lead to edema. Some patients may also show symptoms such as cough and dyspnea. In the clinic, it is necessary to improve the auxiliary examinations and give relevant treatments, such as medication (furosemide, etc.) and surgery (shunt grafting, etc.), to the cause of superior vena cava syndrome by specialized physicians.