Hydrocephalus is a condition in which there is a lack of absorption, blockage of flow or overproduction of the cerebral spinal fluid (CSF) that is found inside the ventricles of the brain. This may result in a buildup of fluid that can cause the pressure inside of the head to increase, and the skull bones to expand to a larger-than-normal appearance.


Hydrocephalus occurs in approximately one out of every 500 births. Hydrocephalus usually occurs due to:

  • Blockage of CSF flow inside of the head
  • Problems with the body absorbing CSF
  • Overproduction of CSF

Hydrocephalus can be congenital (present at birth), or it can be acquired later in life. If not caused by genetics, doctors think many factors—both genetic and environmental—contribute to the condition. In a small percentage of children, a single gene defect on the X chromosome, or another chromosome, causes hydrocephalus. In these cases, the chance for recurrence is higher.

Causes of acquired hydrocephalus may include:

  • Tumor
  • Infection
  • Prematurity
  • Bleeding inside the head
  • Birth injury
  • Abnormal blood vessel formation inside of the head
  • Trauma


Common symptoms of hydrocephalus in younger children may include:

  • A full or bulging fontanelle (soft spot located on the top of the head)
  • Increasing head circumference
  • Seizures
  • Bulging eyes and an inability of the child to look upward with the head facing forward
  • Very noticeable scalp veins
  • Increased irritability
  • High-pitched cry
  • Poor feeding
  • Projectile vomiting
  • Sleepiness or decrease in alertness
  • Developmental delays

In cases where hydrocephalus is not congenital, but is due to a tumor, trauma, infection, or other causes, the symptoms typically seen in older children may include:

  • Complaints of severe headaches
  • Nausea and vomiting
  • Changes in personality, behavior or school performance
  • Problems with bowel or bladder control
  • Increased movement in the arms or legs
  • Seizures

Symptoms of hydrocephalus may resemble other conditions or medical problems. Always consult your child's doctor for a diagnosis.


Hydrocephalus may be diagnosed before birth by a prenatal ultrasound. However, in many cases, hydrocephalus does not develop until the third trimester of the pregnancy. So it may not be seen on ultrasounds performed earlier in pregnancy.

The diagnosis of congenital hydrocephalus may also be made at birth. Though it is sometimes diagnosed in older children who have developmental delays.

Diagnostic tests that may be done to confirm hydrocephalus may include:

  • X-ray 
  • MRI
  • CT scan


Specific treatment for hydrocephalus will be determined by your child's doctor based on your child’s age, overall health and medical history, and the cause of the condition.

The goal of treatment is to reduce the pressure in the child's head and to drain the CSF. Sometimes, medicines or procedures to draw off the extra CSF may be used. Surgery may be needed for some cases, and usually involves placing a mechanical shunting device into the child's head to help drain extra CSF from the brain.

Potential complications from the shunts or surgery can include:

  • Infection
  • Shunt malfunction that results in under-drainage or over-drainage of the CSF
  • Bleeding

Other complications may include fever, nausea or vomiting, irritability, headache, redness and swelling along the area of the tubing, and decreased alertness or complaints of being tired. Following surgery, you will receive instructions on how to care for your child at home and information about signs or symptoms requiring medical care.

Lifelong considerations

Hydrocephalus can affect the brain and a child's development. The key to treating hydrocephalus is early detection, treatment and prevention of infection. A child with hydrocephalus requires frequent medical tests to make sure his shunt is working. Our team at Children’s works with your family to provide education and guidance as your child grows and develops.

Your child's doctor may recommend genetic counseling to discuss the risk of hydrocephalus recurring in future pregnancies, as well as prenatal testing for hydrocephalus.