Hydrocephalus is a buildup of fluid inside the skull that leads to brain swelling.

Hydrocephalus means "water on the brain."

Alternative Names

Water on the brain


Hydrocephalus is due to a problem with the flow of the fluid that surrounds the brain. This fluid is called the cerebrospinal fluid, or CSF. It surrounds the brain and spinal cord, and helps cushion the brain.

CSF normally moves through the brain and the spinal cord, and is soaked into the bloodstream. CSF levels in the brain can rise if:

Too much CSF puts pressure on the brain. This pushes the brain up against the skull and damage brain tissue.

Hydrocephalus may begin while the baby is growing in the womb. It is common in babies who have a myelomeningocele, a birth defect in which the spinal column does not close properly.

Hydrocephalus may also be due to:

In young children, hydrocephalus may be due to:

Hydrocephalus most often occurs in children. Another type, called normal pressure hydrocephalus, may occur in adults and the elderly.


Symptoms of hydrocephalus depend on:

In infants with hydrocephalus, it causes the fontanelle (soft spot) to bulge and the head to be larger than expected. Early symptoms may also include:

Symptoms that may occur in older children can include:

Exams and Tests

The doctor or nurse will examine the baby. This may show:

Head circumference measurements, repeated over time, may show that the head is getting bigger.

A head CT scan is one of the best tests for identifying hydrocephalus. Other tests that may be done include:


The goal of treatment is to reduce or prevent brain damage by improving the flow of CSF.

Surgery may be done to remove a blockage, if possible.

If not, a flexible tube called a shunt may be placed in the brain to re-route the flow of CSF.  The shunt sends CSF to another part of the body, such as the belly area, where it can be absorbed.

Other treatments may include:

The child will need regular check-ups to make sure there are no further problems. Tests are regularly done to check the child's developmental and for intellectual, neurological, or physical problems.

Visiting nurses, social services, support groups, and local agencies can provide emotional support and assist with the care of a child with hydrocephalus who has significant brain damage.

Outlook (Prognosis)

Without treatment, up to 6 in 10 people with hydrocephalus will die. Those who survive have different amounts of  intellectual, physical, and neurological disabilities.

The outlook depends on the cause. Hydrocephalus that is not due to an infection has the best outlook. Persons with hydrocephalus caused by tumors usually do very poorly.

Most children with hydrocephalus that survive for 1 year will have a fairly normal life span.

Possible Complications

The shunt may become blocked. Symptoms of such a blockage include headache and vomiting. Surgeons may be able to help the shunt open without having to replace it.

There may be other problems with the shunt, such as kinking, tube separation, or infection in the area of the shunt.

Other complications may include:

When to Contact a Medical Professional

Seek immediate medical care if your child has any symptoms of this disorder. Go to the emergency room or call 911 if emergency symptoms occur, which include:

You should also call your health care provider if the child has been diagnosed with hydrocephalus and the condition gets worse and you are unable to care for him or her at home.


Protect the head of an infant or child from injury. Prompt treatment of infections and other disorders associated with hydrocephalus may reduce the risk of developing the disorder.


Kinsman SL, Johnston MV. Hydrocephalus. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 585.11.  

Rosenberg GA. Brain edema and disorders of cerebrospinal fluid circulation. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann; 2008:chap 63.  

Review Date: 11/12/2012
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.
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