Written by Amanda Delgado | Published on August 15, 2012
Medically Reviewed by George Krucik, MD

What is Hydrocephalus

Hydrocephalus is a condition that occurs when fluid builds up in the skull and causes the brain to swell. The name literally means “water on the brain.”

Brain damage can occur as a result of the fluid buildup. This can lead to impaired developmental, physical, and intellectual functions. It requires treatment to prevent serious complications.

Hydrocephalus mainly occurs in children and adults over 60, but younger adults can get it too. The National Institute of Neurological Disorders and Stroke estimates that the condition occurs in roughly one in every 500 children (NINDS).

What Causes Hydrocephalus?

Cerebrospinal fluid (CSF) flows through your brain and spinal cord in normal conditions. Under certain abnormal conditions, the amount of CSF in your brain increases. These include:

  • a blockage that prevents CSF from flowing normally
  • decrease in the ability of blood vessels to absorb it
  • your brain produces an excess amount of it

When you have too much of this fluid, it puts your brain under too much pressure. Your brain tissue can be damaged as your brain swells within your skull.

Underlying Causes

In some cases, hydrocephalus starts before a baby is born. This can result from:

  • a birth defect in which the spinal column doesn’t close
  • genetic defects
  • certain infections that occur during pregnancy, such as rubella

This condition can also occur in infants, toddlers, and older children due to:

  • central nervous system infections such as meningitis, especially in babies
  • bleeding in the brain during or shortly after delivery, especially in babies born prematurely
  • injuries that occur before, during, or after delivery
  • trauma
  • central nervous system tumors

Normal Pressure Hydrocephalus

When hydrocephalus occurs in adults, CSF levels rise but the amount of pressure is usually normal. It still causes the brain to swell and can lead to impaired functioning. In adults, this condition usually results from conditions that prevent CSF from flowing. However, in some cases, there is no known cause.

You might be at higher risk of it if you have experienced any of the following:

  • infections such as meningitis
  • head injuries
  • bleeding from a blood vessel in your brain
  • brain surgery

Recognizing Potential Signs of Hydrocephalus


Early signs of hydrocephalus in infants include:

  • bulging fontanelle, or soft spot on the surface of the skull
  • rapid increase in head circumference
  • eyes that look down
  • seizures
  • fussiness
  • vomiting
  • sleepiness

Toddlers and Older Children

Symptoms that affect toddlers and older children include:

  • short, high-pitched cries
  • personality changes
  • facial changes
  • crossed eyes
  • headaches
  • muscle spasms
  • slow growth
  • trouble eating
  • extreme sleepiness
  • irritability
  • loss of coordination
  • loss of bladder control

Normal Pressure Hydrocephalus

The symptoms for this form of the condition usually begin slowly. One of the earliest signs is falling suddenly without losing consciousness. Other common symptoms include:

  • changes in the way you walk
  • impaired mental functions, such as memory problems
  • trouble controlling urine
  • trouble controlling stools
  • headaches

How Is Hydrocephalus Diagnosed?

If your doctor suspects hydrocephalus in your child, he or she will perform a physical exam to look for signs and symptoms. Your doctor will check for eyes that look sunken in, slow reflexes, bulging fontanelle, and a head circumference that is larger than normal.

Your doctor might also use an ultrasound to get a closer look at the brain. These use high-frequency sound waves to create images of the brain.

Magnetic resonance imaging (MRI) scans can be used to look for signs of excess CSF. MRIs use a magnetic field and radio waves to make a cross-sectional image of the brain.

Computerized tomography (CT) scans can also help diagnose hydrocephalus in children and adults. CT scans use several different X-rays to form a cross-sectional image of the brain. These scans can show enlarged ventricles that result from too much CSF.

How Is Hydrocephalus Treated?

The National Institutes of Health states that up to six in 10 people with hydrocephalus die without treatment (NIH). In other words, quick treatment is absolutely essential.

Treatment may not reverse brain damage already done—the goal is to prevent further brain damage. This primarily involves helping CSF flow as it normally should.

Shunt Insertion

In most cases, a shunt is surgically inserted. The shunt is a drainage system made of a long tube with a valve. The valve helps CSF flow at a normal rate and in the right direction. One end of the tube is inserted in the brain, and the other end is typically inserted into the chest or abdomen. Excess fluid then drains from the brain and out the other end of the tube, where it is more easily absorbed. The shunt is typically needed permanently and has to be monitored regularly.


A procedure called a ventriculostomy can be performed as an alternative to having a shunt inserted. This involves making a hole at the bottom of a ventricle or in between them to allow CSF to leave the brain.

What is the Outlook for a Patient With Hydrocephalus?

The outlook for someone suffering from hydrocephalus depends largely on the extent of their symptoms. Many children suffer lifelong brain damage. By working with several professionals including pediatricians, special education teachers, mental health providers, occupational therapists, developmental therapists, and pediatric neurologists they may be able to lessen the lifelong effects, learning to manage their disability.

Adults with severe symptoms of hydrocephalus might need to work with occupational therapists. Some might need the care of medical specialists who focus on dementia.

The long-term effects of this condition vary widely, so a more case-specific outlook is best obtained through your doctor.

Reducing Your Child’s Risk for Hydrocephalus

You can’t prevent hydrocephalus, but you can lower your risk and your child’s risk for developing the condition.

Make sure you get prenatal care during pregnancy. This can help reduce your chance of going into premature labor, which can lead to hydrocephalus.

Getting vaccinations as part of your normal health care can help prevent illnesses and infections that are linked to hydrocephalus. Having regular screenings can also ensure that you get prompt treatment for illnesses or infections that could put you at risk of getting hydrocephalus.

Use safety equipment, such as helmets, to prevent head injuries when doing activities like riding a bike. You can also lower your risk of head injuries by always wearing a seat belt.

Young children should always be secured in a car seat. You can also prevent head injuries by making sure your baby equipment, such as strollers, meets safety standards.

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