Acquired hydrocephalus — This refers to hydrocephalus that occurs later in life.

Central nervous system (CNS) — This is made up of the brain and spinal cord.

Cerebrospinal fluid (CSF) — This is the water-like fluid that circulates around the brain and spinal cord. It serves to cushion and protect the CNS, as well as to balance nutrients and remove waste products.

Communicating hydrocephalus — This is a type of hydrocephalus that results from an overproduction of cerebrospinal fluid or an underabsorption of fluid into the bloodstream.

Congenital hydrocephalus — This is a type of hydrocephalus that is present at birth.

Hydrocephalus — Hydrocephalus is an abnormal accumulation of water-like fluid in the head. From the Greek "hydro," meaning "water," and "cephalus," meaning "head."

Non-communicating hydrocephalus — This is a type of hydrocephalus that results from a blockage that interferes with the flow of CSF. It is also referred to as obstructive hydrocephalus.

Obstructive hydrocephalus — This is a type of hydrocephalus that results from a blockage that interferes with the flow of CSF. It is also referred to as non-communicating hydrocephalus.

Shunt — This is an implantable device that drains excess fluid from the brain and spinal cord, and diverts it to another part of the body, such as the abdomen or heart, where it can be absorbed.

Ventricles — These are the spaces within the brain where cerebrospinal fluid is made.