Patients with left posterior head pain mainly consider the following causes: 1. If the pain is pulsating or throbbing, consider migraine; 2. If the patient’s left posterior head pain is persistent, and the pain gradually increases, accompanied by nausea, vomiting and other symptoms, consider that it may be caused by brain tumor or brain occupancy; 3. The patient’s left posterior head pain may also be caused by occipital neuralgia caused by it. The diagnosis of neuralgia is usually easy to appear when the patient’s resistance is low, when he is cold, or because cervical spondylosis causes stimulation to the occipital nerve, which also easily causes headache; 4. Pain in the back left part of the patient’s head may also be a headache of the nature of neurological weakness, which is generally related to poor sleep, exertion and mental tension.