The common causes of left facial neuralgia include trigeminal neuralgia, migraine and herpes zoster. 1. Trigeminal neuralgia: it can be manifested as repeated episodes of transient electric shock-like, cut-like, tear-like severe pain in the distribution area of the trigeminal nerve on the left side of the face. 2. Migraine: manifested as one side or both sides of the throbbing severe headache, and most often occurs on the side of the head, in severe cases can be radiated to the left side of the face, the left side of the face pain. 3. Herpes zoster: Herpes zoster on the left side of the face can be manifested as neuralgia on the left side of the face, with aggregated herpes on the surface of the skin, which is mainly caused by herpes virus attack. Neuralgia on the left side of the face can also be caused by other reasons, it is recommended that patients seek medical advice in a timely manner, under the guidance of the doctor to identify the causes, targeted treatment.