Water on the brain, also known as hydrocephalus, is defined by the National Institutes of Health (NIH) as “a build up of fluid inside the skull, leading to brain swelling.” The fluid in question is cerebrospinal fluid (CSF), which normally cushions the brain and the spinal cord; the CSF also delivers nutrients to the brain, and transports the waste away from the brain. A patient with water on the brain, however, have either a blockage or overproduction of CSF; the excess of CSF puts pressure on the brain, which can lead to damage of brain tissue.
The Mayo Clinic states that one out of every 500 children are diagnosed with water on the brain. The disorder can be present at birth or symptoms can develop slightly later; the damage, however, starts while the child is developing in the womb. If water on the brain is left untreated, the death rate is 50 to 60 percent, according to the NIH; however, the condition can be treated by relieving the pressure, either through surgery or a shunt.