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Migraine is a neurological disease characterized by recurrent moderate to severe headaches often in association with a number of autonomic nervous system symptoms. The word is derived from the Greek ἡμικρανία (''hemikrania''), "pain on one side of the head",〔 on Perseus〕 from ἡμι- (''hemi-''), "half", and κρανίον (''kranion''), "skull". Typically, the headache affects one half of the head, is pulsating in nature, and lasts from 2 to 72 hours. Associated symptoms may include nausea, vomiting, and sensitivity to light, sound, or smell. The pain is generally made worse by physical activity.〔 (as PDF )〕 Up to one-third of people with migraine headaches perceive an aura: a transient visual, sensory, language, or motor disturbance which signals that the headache will soon occur.〔 Occasionally, an aura can occur with little or no headache following it. Migraines are believed to be due to a mixture of environmental and genetic factors. About two-thirds of cases run in families.〔 Changing hormone levels may also play a role, as migraines affect slightly more boys than girls before puberty, but about two to three times more women than men.〔 The risk of migraines usually decreases during pregnancy. The exact mechanisms of migraine are not known. It is, however, believed to be a neurovascular disorder.〔 The primary theory is related to increased excitability of the cerebral cortex and abnormal control of pain neurons in the trigeminal nucleus of the brainstem. Initial recommended management is with simple pain medication such as ibuprofen and paracetamol (also known as acetaminophen) for the headache, medication for the nausea, and the avoidance of triggers. Specific agents such as triptans or ergotamines may be used by those for whom simple analgesics are not effective. Globally, approximately 15% of the population is affected by migraines at some point in life. ==Signs and symptoms== Migraines typically present with self-limited, recurrent severe headache associated with autonomic symptoms.〔〔 About 15–30% of people with migraines experience migraines with an aura〔 and those who have migraines with aura also frequently have migraines without aura.〔 The severity of the pain, duration of the headache, and frequency of attacks is variable.〔 A migraine lasting longer than 72 hours is termed status migrainosus. There are four possible phases to a migraine, although not all the phases are necessarily experienced:〔 # The prodrome, which occurs hours or days before the headache # The aura, which immediately precedes the headache # The pain phase, also known as headache phase # The postdrome, the effects experienced following the end of a migraine attack 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Migraine」の詳細全文を読む スポンサード リンク
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