Upper limb and facial vascular varices, edema and bruising are symptoms of superior vena cava syndrome, also known as superior vena cava obstruction syndrome, which is a syndrome caused by venous obstruction in the superior vena cava or its surrounding lesions, resulting in obstruction of blood flow in the superior vena cava, leading to varices, edema and bruising in the upper limbs and face. Differential diagnosis of varicose, edema and cyanosis of upper limbs and facial vessels: I. Medical history For male patients over 40 years old with a history of long-term aspiration, chest pain, bloody sputum, repeated recurrent pneumonia or pulmonary atelectasis, they must be alert to the possibility of bronchopulmonary cancer. Those with enlarged peripheral lymph nodes, especially cervical lymph nodes, should consider malignant lymphoma. The possibility of chronic fibrous mediastinitis should be thought of if there was a history of severe cell trauma or more persistent chronic lung infection months or years ago. Superior vena cava thrombosis caused by the installation of an artificial pacemaker or the placement of a floating catheter through the superior vena cava. Second, the following three simple clinical tests can be performed for diagnosis 1, clenched fist exercise test: clenched fist and then relaxed, so repeatedly for 30 times a minute, to measure the change of elbow venous pressure before and after. Normal people should have no change, while patients with superior vena cava obstruction have a positive elbow venous pressure rise of 0.98kPa (10mmH2O) after fist clenching exercise (negative for congestive heart failure). 2.Contradictory phenomenon: Normal people measure the venous pressure, the venous pressure decreases during inspiration because of the decrease of thoracic pressure, while the venous pressure rises during exhalation. When the site of obstruction is below the entrance of the odd vein, most cases appear the phenomenon that the venous pressure of the upper extremity rises during inspiration and falls during expiration. 3.Chest band test: Tighten the lower part of chest with wide chest band, if the obstruction is below the opening of odd vein, then the chest band compresses the lateral branch circulation, and the venous pressure of upper limb rises above 0.196kPa (20mmH2O).