”You’ve got water in your brain” is what people often say in life when they describe someone as stupid or dumb. So can water in the brain really affect our intelligence? The medical name for “water in the brain” can be called hydrocephalus or hydrocephalus, and the next name for “water in the brain” is hydrocephalus. Hydrocephalus is not a disease, it is a pathological result caused by a variety of causes. Hydrocephalus is a condition in which the cerebrospinal fluid is increased due to excessive secretion or (and) impaired circulation and absorption of cerebrospinal fluid due to cranial disorders, and the ventricular system is enlarged or (and) the subarachnoid space is enlarged. Its typical symptoms are headache, vomiting, blurred vision, optic nerve papillary edema, occasional diplopia, vertigo and seizures. In untreated congenital hydrocephalus, about half of the children die within a year and a half, although 20% of them can stop developing. Neurological deficits in patients with hydrocephalus are positively correlated with the severity of hydrocephalus and should be treated aggressively.