The patient’s symptoms of headache and vomiting on the left side are considered to be caused by migraine. If the pain-sensitive structures in the head are triggered for some reason, the patient will have episodic headache, and after stimulating sympathetic and gastrointestinal nerves, the patient will experience nausea and vomiting. If the headache and vomiting are caused by migraine, the patient’s headache symptoms may be partially relieved after vomiting. If the patient has frequent episodes of left-sided headache and vomiting, it should be considered as primary headache, which is caused by migraine, and oral pain medication can be taken to relieve the headache. If the patient has gradual pain on the left side, and the pain is gradually aggravated and persists, and finally the symptoms of vomiting appear, the patient must be alert to the left intracranial tumor or intracranial occupancy. It is important to consult a hospital early and have an MRI of the head to clarify.