Hydrocephalus comes from the Greek words “hydro” meaning water and “cephalic” meaning brain. It is caused by a build up of cerebrospinal fluid (CSF) in the ventricles of the brain resulting in increased pressure. Hydrocephalus can be congenital (present at birth) and caused by, for example, aqueduct stenosis or Dandy Walker cysts, or it can be acquired after birth as a result of, for example, a haemorrhage (stroke), prematurity, Meningitis, a head injury, tumours, or in association with Spina Bifida. Sometimes the cause is unknown. Hydrocephalus can lead to problems that affect everyday life such as difficulties with concentration and short term memory, co-ordination, motivation, and organisational skills. Most forms of hydrocephalus require treatment. This is usually surgical and involves inserting a shunting device to drain the excess CSF.