The left side of the headache: First, consider the migraine, migraine clinical etiology is not very clear, consider with metabolic factors, endocrine factors and environmental factors, etc., most common in young and middle-aged patients, due to poor rest, exertion and tension can appear after the head CT or magnetic examination did not have a positive performance. Treatment can be given to symptomatic painkillers orally, clinically commonly used ibuprofen, or acetaminophen, and in severe cases can also be considered to take oral trabectedin analog painkillers and ergotamine preparations. Second, the left half of the head pain can also be seen in cerebrovascular disease, to cerebral hemorrhage is common. Generally, there is a history of hypertension, the symptoms appear sharply and suddenly, and can be accompanied by symptoms of neurological deficits, such as numbness and weakness of the limbs, and speech clumsiness, etc. Generally, the diagnosis can be confirmed by checking the CT examination of the head. Surgery or conservative treatment can be given according to the amount of bleeding. Third, the left side of the headache can also be seen in sinusitis or otitis media patients, in addition to the left side of the headache, can also be accompanied by nasal congestion, pus flow, ear pain symptoms, if necessary, it is recommended to consult the Pentacenter.