Hydrocephalus is often described as water on the brain because it is derived from two words “hydro” meaning water, and “cephalus” referring to the head. It is a condition where excess cerebrospinal fluid (CSF) builds up within the fluid-containing cavities of the brain called ventricles. This fluid is necessary for brain function, but too much can increase pressure in the brain and damage brain tissue. Hydrocephalus can occur at any age, but is most common in infants and adults age 60 and older.

Causes and Risk Factors

Hydrocephalus is usually caused by a disruption of the drainage system for CSF. This colorless fluid is produced in the brain and carries nutrients to cells, absorbs shock, and regulates pressure. It normally flows through and around the brain and then down the spinal cord, where it is absorbed by the blood stream. When the drainage system does not work properly, the ventricles swell with excess fluid and this raises the pressure within the brain.


Symptoms very greatly, but some common symptoms include the following:


  • Abnormal enlargement of head
  • Nausea/vomiting
  • Downward deviation of an infant’s eyes
  • Drowsiness
  • Irritability


  • Headache
  • Difficulty in waking up or staying awake
  • Loss of coordination or balance
  • Vision impairment
  • Memory loss


Treatment may involve implanting a device called a shunt. This allows the excess fluid to drain out of the skull and into another area such as the abdomen or heart, where it is absorbed in the body. Once inserted, the shunt usually stays in place for the duration of the patient’s life. Sometimes additional surgeries are required to revise the shunt system. This ongoing condition requires continued follow-up care, but any complications that arise can usually be dealt with successfully.