Well, hydrocephalus is a condition where there is excessive fluid accumulation in ventricles leading to dilatation of the ventricles This may cause Mass effect and raised icp and requires treatment only then.Signs and symptons include headache,projectile vomiting,enlarging head,bulging fontanelles in children and blurring if vision in elderly.CT scan confirm the diagnosis.Sometimes in a condition called Arrested hudrocephalus dont require treatment as there is no progressive deterioration.Treatment is mainly surgical by placement of a shunt but some drugs can be used to lower icp in initial stages.