What is Hydrocephalus?

Hydrocephalus is a condition that affects the brain and how it functions. It can occur at any age but is more common in infants.

A clear, saltwater-like liquid called cerebro-spinal fluid (CSF) surrounds the brain. This fluid protects and nourishes the brain. It carries away waste from brain cells and contains important chemicals and nutrients.

Every day the brain produces about a pint of CSF which flows in a continuous circuit through the brain cavities (ventricles) and over the surface of the brain and spinal cord until it is absorbed by the body.

If the flow of CSF is blocked at any point, the fluid cannot drain away and will collect in the ventricles inside the brain. This causes them to swell which causes the surrounding tissue to stretch. This can also mean that the surface of the brain is pressed against the inside of the skull.

In babies and infants, the head will get bigger as the ventricles swell and increase the size of the brain. In older children and adults, the head size cannot increase, as the bones that form the skull are completely fused together.

The information in this section is available in a leaflet, “What is Hydrocephalus”. This may be downloaded in PDF format from our library.