Hydrocephalus is a buildup of fluid inside the skull that leads to the brain pushing against the skull.
Hydrocephalus means "water on the brain."
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. The fluid surrounds the brain and spinal cord and helps cushion the brain.
CSF normally moves through the brain and around the spinal cord, and then is absorbed 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 damages 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 older people.
Symptoms of hydrocephalus depend on:
In infants, hydrocephalus 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:
The health care provider will examine the baby. This may show:
Repeated head circumference measurements 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 reroute 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 will be done regularly to check the child's development, and to look for intellectual, neurological, or physical problems.
Visiting nurses, social services, support groups, and local agencies can provide emotional support and help with the care of a child with hydrocephalus who has serious brain damage.
Without treatment, up to 6 in 10 people with hydrocephalus will die. Those who survive will 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. People with hydrocephalus caused by tumors will often do very poorly.
Most children with hydrocephalus who survive for 1 year will have a fairly normal lifespan.
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:
Seek medical care right away if your child has any symptoms of this disorder. Call 911 or the local emergency number or go to the emergency room if emergency symptoms occur, such as:
You should also contact your provider if:
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.
Gunny RS, Saunders DE, Argyropoulou MI. Paediatric neuroradiology. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. Grainger & Allison's Diagnostic Radiology. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 76.
Ho WS, Kestle JRW. Hydrocephalus in children: etiology and overall management. In: Winn HR, ed. Youmans and Winn Neurological Surgery. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 223.
Kinsman SL, Johnston MV. Congenital anomalies of the central nervous system. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 609.
Rosenberg GA. Brain edema and disorders of cerebrospinal fluid circulation. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 88.
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.