Left migraine is mainly seen in the following conditions: 1. Migraine, common in young and middle-aged women with recurrent attacks, mainly manifested as migraine, often accompanied by nausea, vomiting, blurred vision, photophobia and phonophobia, etc. The duration of headache is 4-72 hours, and the headache is pulsating moderate pain, some of which can be improved after resting on their own. Frequent migraine attacks can be prevented by taking oral calcium antagonists such as flunarizine hydrochloride capsules or anti-anxiety drugs such as amitriptyline. 2. Left-sided occipital neuralgia, where the occipital nerve is responsible for scalp nociceptive nerves, and inflammation of the left-sided occipital nerve or cervical spine disease compressing and stimulating the occipital nerve will lead to pain on the left side of the scalp, which will continue to be dull pain, as well as pins and needles-like pain. 3. Left-sided intracranial diseases, such as left-sided Large cerebral infarction, left-sided cerebral hemorrhage, left-sided intracranial tumor, etc., can cause left-sided headache, accompanied by nausea and vomiting.