The numbness on the right side of the face may be caused by physiological factors, facial nerve palsy, acute cerebrovascular disease, brain tumor and other factors. 1. Physiological factors: in cold weather, the right side of the face is frequently stimulated by cold wind, which will make the right side of the face appear physiological numbness, which is a normal physiological manifestation, strengthen the warmth measures, and avoid the cold wind stimulation, and can be restored to normal by itself. 2. Facial nerve palsy: it may be related to viral infection, resulting in damage to the facial nerve, the right side of the face will appear numbness, there may also be a crooked corner of the mouth, eyelid ptosis and other symptoms. 3. Acute cerebrovascular disease: for example, acute cerebral hemorrhage or acute cerebral infarction, which may lead to damage to the nerves innervating the right side of the face, and the right side of the face will become numb, accompanied by numbness of the limbs, speech impediment, nausea, vomiting and other symptoms. 4. Brain tumor: when there is a tumor in the skull, with the increase of tumor volume, it may compress and stimulate the facial nerve on the right side, which may lead to numbness on the right side of the face, accompanied by headache, dizziness, nausea and vomiting and other symptoms. If the patient has numbness on the right side of the face for a long time and physiological factors are excluded, it is recommended to consult a doctor for examination and treatment to avoid delaying the condition.