Superior vena cava obstruction is clinically known as superior vena cava syndrome, which is characterized by dyspnea, swelling of the head and neck, edema of the upper extremities, headache and dizziness. This is because the superior vena cava is the main trunk that organizes the venous blood in the upper body and injects it into the right atrium in the chest. When the superior vena cava is obstructed, the blood return to the upper body will be blocked, resulting in head and neck swelling, headache and dizziness, and upper limb edema, etc. Compression of the surrounding tissues, such as the trachea, will result in the symptom of respiratory distress. The common cause of this kind of performance is tumor, due to the swelling is too big to compress the superior vena cava caused by its return obstruction. Once the symptoms of dyspnea and facial edema appear, they are very critical and need to be treated immediately, otherwise they may cause life-threatening conditions such as intracranial hypertension. If the above symptoms occur, the patient should keep the head high and feet low lying posture, and immediately send to the doctor for treatment, do not treat by themselves.