Half of the face is swollen, painless and itchy may be caused by gingivitis, superior vena cava obstruction and other diseases, the patient should consult a doctor in time, clear the cause of the disease after treatment. 1. Gingivitis: half of the face is swollen, painless and itchy, which may be caused by plaque gingivitis, and the patient may also have bleeding gums and changes in the texture of the gums, so the patient should pay attention to oral hygiene, and use hydrogen peroxide to rinse the oral cavity if necessary. 2. Superior vena cava obstruction: Tumor, thrombus and other factors lead to the superior vena cava obstruction will cause the patient to appear on one side of the face swollen but painless, there will be dyspnea, increased intracranial pressure and other symptoms, you should consult a doctor in a timely manner. All of the above drugs should be used under the guidance of a doctor.