Idiopathic intracranial hypertension is a neurological syndrome characterized by symptoms and signs of intracranial hypertension in the absence of structural lesion, hydrocephalus or infection.

It is more frequent in young or middle-aged obese women. The most frequent clinical manifestation is headaches associated with visual obscurations, decreased visual acuity and campimetric defects (scotomas).

Sometimes double vision due to involvement of the abducens nerve (VI cranial nerve) may appear. In the fundus there is evidence of bilateral papilledema (papilledema). It may cause irreversible blindness.