The causes and early symptoms of facial palsy mainly depend on whether it is central facial palsy or peripheral facial palsy, as follows: 1. Peripheral facial palsy: the common cause is very much related to viral infection, commonly caused by cold before onset or upper respiratory tract infection, the early symptoms of this kind of peripheral facial palsy commonly include incomplete eyelid closure, crooked corners of the mouth, shallowing of the frontal lines on one side, etc. These may be These may be early symptoms of facial palsy; 2. Central facial palsy: early symptoms are relatively more complex, and may include numbness and weakness of the limbs, slurred speech, etc. Central facial palsy may also be accompanied by distorted corners of the mouth, and rarely, shallow frontal lines on one side and incomplete eyelid closure, which are the main symptoms that distinguish peripheral facial palsy.