贝尔氏面瘫患者面神经存在炎症、肿胀。面神经需要穿过位于颞骨岩部，医学上也称为法娄皮欧氏管（the Fallopian canal）。面神经这段穿行于狭长、迂曲而没有可扩展性的面神经管内，一旦损坏或者收到创伤，发生的炎症反应导致神经肿胀，“隧道”内压力升高造成神经挤压，目前认为这是造成面神经麻痹的主要病理过程，也称为面神经炎性面瘫。
Can the air conditioner really blow out facial paralysis? There is inflammation and swelling in the facial nerve of Bell's palsy. The facial nerve needs to pass through the petrous portion of the temporal bone, also known medically as the Fallopian canal. The facial nerve passes through a long, narrow, tortuous and non-expansible facial nerve canal. Once damaged or traumatized, the inflammation causes nerve swelling, and the pressure in the tunnel increases, resulting in nerve compression. Now it is considered that this is the main pathological process of facial nerve paralysis, also known as facial nerve inflammatory facial paralysis.