Hydrocephalus is the buildup of fluid in cavities called ventricles deep within the brain. The excess fluid increases the size of the ventricles and puts pressure on the brain.

Cerebrospinal fluid usually flows through the ventricles and bathes the brain and spinal column. But the pressure of too much cerebrospinal fluid can damage brain tissues and cause a range of symptoms related to brain function.

Hydrocephalus can happen at any age, but it occurs more often among infants and among adults 60 and older. Surgery can restore and maintain healthy cerebrospinal fluid levels in the brain. Therapies can manage symptoms resulting from hydrocephalus.


The symptoms of hydrocephalus can vary by age.


Common symptoms of hydrocephalus in infants include:

Changes in the head

  • A head that is larger than usual.
  • A rapid increase in the size of an infant's head.
  • A bulge or tense soft spot on the top of the head.

Physical symptoms

  • Nausea and vomiting.
  • Sleepiness or sluggishness, known as lethargy.
  • Irritability.
  • Poor eating.
  • Seizures.
  • Eyes fixed downward, known as sunsetting of the eyes.
  • Problems with muscle tone and strength.

Toddlers and older children

Among toddlers and older children, symptoms might include:

Physical symptoms

  • Headache.
  • Blurred or double vision.
  • Eye movements that are not usual.
  • Enlargement of a toddler's head.
  • Sleepiness or sluggishness.
  • Nausea or vomiting.
  • Trouble with balance.
  • Poor coordination.
  • Poor appetite.
  • Loss of bladder control or urinating often.

Behavioral and cognitive changes

  • Irritability.
  • Change in personality.
  • Decline in school performance.
  • Delays or problems with earlier gained skills, such as walking or talking.

Young and middle-aged adults

Common symptoms in this age group include:

  • Headache.
  • Sluggishness.
  • Loss of coordination or balance.
  • Loss of bladder control or needing to urinate often.
  • Vision problems.
  • Decline in memory, concentration and other thinking skills that may affect job performance.

Older adults

Among adults 60 and older, the more common symptoms of hydrocephalus are:

  • Loss of bladder control or needing to urinate often.
  • Memory loss.
  • Progressive loss of other thinking or reasoning skills.
  • Trouble walking, often described as shuffling or the feeling of the feet being stuck.
  • Poor coordination or balance.

When to see a doctor

Seek emergency medical care for infants and toddlers with these symptoms:

  • A high-pitched cry.
  • Problems with sucking or feeding.
  • Recurrent vomiting with no clear cause.
  • Seizures.

Seek prompt medical attention for other hydrocephalus symptoms in any age group.

More than one condition can cause the problems associated with hydrocephalus. It's important to get a timely diagnosis and appropriate care.


Hydrocephalus is caused by an imbalance between how much cerebrospinal fluid is produced and how much is absorbed into the bloodstream.

Tissues lining the ventricles of the brain produce cerebrospinal fluid. It flows through the ventricles by way of channels. The fluid eventually flows into spaces around the brain and spinal column. It's absorbed primarily by blood vessels in tissues on the surface of the brain.

Cerebrospinal fluid plays an important role in brain function by:

  • Allowing the relatively heavy brain to float within the skull.
  • Cushioning the brain to prevent injury.
  • Removing waste products of the brain's metabolism.
  • Flowing back and forth between the brain cavity and spinal column. This flow maintains a constant pressure within the brain and allows for changes in blood pressure in the brain.

Too much cerebrospinal fluid in the ventricles can occur for one of the following reasons:

  • Obstruction. Partial blockage of the flow of cerebrospinal fluid is the most common cause of too much cerebrospinal fluid in the ventricles. A blockage may happen from one ventricle to another or from the ventricles to other spaces around the brain.
  • Poor absorption. Less common is a problem with absorbing cerebrospinal fluid. This is often related to inflammation of brain tissues from disease or injury.
  • Overproduction. Rarely, cerebrospinal fluid is created more quickly than it can be absorbed.
Brain ventricles

Risk factors

Much of the time, the cause of hydrocephalus is not known. However, developmental or medical problems can contribute to or trigger hydrocephalus.


Hydrocephalus may be present at or before birth, known as congenital hydrocephalus. Or it can occur shortly after birth. Any of the following incidents may cause hydrocephalus in newborns:

  • The central nervous system developed in a way that blocks the flow of cerebrospinal fluid.
  • Bleeding occurred within the ventricles. This is a possible complication of premature birth.
  • There was an infection in the uterus during pregnancy, such as rubella or syphilis. An infection can cause swelling in the brain tissues of an unborn baby.

Other contributing factors

Other factors that can contribute to hydrocephalus among any age group include:

  • Tumors of the brain or spinal cord.
  • Central nervous system infections, such as bacterial meningitis or mumps.
  • Bleeding in the brain from a stroke or head injury.
  • Other traumatic injury to the brain.


In most cases, hydrocephalus worsens. Without treatment, hydrocephalus leads to complications. Complications may include learning disabilities or developmental and physical disabilities. Complications of this condition also can result in death. When hydrocephalus is mild and it's treated, there may be few, if any, serious complications.


A diagnosis of hydrocephalus is usually based on:

  • Your symptoms.
  • A general physical exam.
  • A neurological exam.
  • Brain-imaging tests.

Neurological exam

The type of neurological exam depends on a person's age. A health care professional might ask questions and conduct simple tests to judge muscle condition, movement, well-being and function of sensory abilities.

Brain imaging

Imaging tests can help diagnose hydrocephalus. They also can pinpoint underlying causes of symptoms. Imaging tests include:

  • Ultrasound. This test is often the first test for infants because it's a simple, low-risk procedure. The ultrasound device is placed over the soft spot on the top of the baby's head. Ultrasound also might find hydrocephalus before birth during routine prenatal exams.
  • MRI. This test uses radio waves and a magnetic field to produce detailed images of the brain. This test is painless, but it is noisy and requires lying still.

    MRI scans can show enlarged ventricles caused by excess cerebrospinal fluid. MRI also can be used to find causes of hydrocephalus or other conditions contributing to symptoms.

    Children might need medicine to help them feel calm, known as mild sedation, for some MRI scans. However, some hospitals use a fast version of MRI that usually doesn't require sedation.

  • CT scan. This specialized X-ray technology produces cross-sectional views of the brain. Scanning is painless and quick. But this test also requires lying still, so a child usually receives a mild sedative.

    CT scans show less detail than do MRI scans. And CT technology causes exposure to a small amount of radiation. CT scans for hydrocephalus usually are used only for emergency exams.


One of two surgical treatments can be used to treat hydrocephalus.


The most common treatment for hydrocephalus is the surgical insertion of a drainage system, called a shunt. It consists of a long, flexible tube with a valve that keeps fluid from the brain flowing in the right direction and at the proper rate.

One end of the tubing is usually placed in one of the brain's ventricles. The tubing is then tunneled under the skin to another part of the body such as the stomach or a heart chamber. This allows excess fluid to be more easily absorbed.

People who have hydrocephalus usually need a shunt system for the rest of their lives. They require regular monitoring.

Endoscopic third ventriculostomy

Some people may have a surgery called endoscopic third ventriculostomy. The surgeon uses a small video camera to see inside the brain. Then the surgeon makes a hole in the bottom of a ventricle. This allows cerebrospinal fluid to flow out of the brain.

Complications of surgery

Both surgical procedures can result in complications. Shunt systems can stop draining cerebrospinal fluid. Or shunt systems may poorly regulate drainage because of mechanical problems, a blockage or infections. Complications of ventriculostomy include bleeding and infections.

Complications of surgery require prompt attention. Another surgery or other interventions may be needed. Fever or symptoms of hydrocephalus should prompt an appointment with your health care professional.

Other treatments

Some people with hydrocephalus, particularly children, might need supportive therapies. Need for these therapies depends on the long-term complications of hydrocephalus.

Children's care teams might include:

  • Pediatrician or physiatrist, who oversees the treatment plan and medical care.
  • Pediatric neurologist, who specializes in diagnosing and treating neurological conditions in children.
  • Occupational therapist, who specializes in therapy to develop everyday skills.
  • Developmental therapist, who specializes in therapy to help your child develop age-appropriate behaviors, social skills and interpersonal skills.
  • Mental health professional, such as a psychologist or psychiatrist.
  • Social worker, who helps the family get needed services and plan for transitions in care.

Children who are in school may need special education. Special education teachers address learning disabilities, determine educational needs and help find needed resources.

Adults with more serious complications might need the services of occupational therapists or social workers. Or they may need to see specialists in dementia care or other medical specialists.

Shunt system

Coping and support

With the help of therapies and educational services, many people with hydrocephalus live with few limitations.

If you have a child with hydrocephalus, there are many resources available to provide emotional and medical support. Children with developmental disabilities might be eligible for government-sponsored health care and other support services. Check with your state or county social services agency.

Hospitals and organizations serving people with disabilities are good resources for emotional and practical support. Members of your health care team also can help. Ask for help connecting with other families who are coping with hydrocephalus.

Adults living with hydrocephalus might find valuable information from organizations dedicated to hydrocephalus education and support, such as the Hydrocephalus Association.

Should you be vaccinated against meningitis?

Ask your child's or your health care team if you or your child should receive a vaccine against meningitis, once a common cause of hydrocephalus. The Centers for Disease Control and Prevention recommends meningitis vaccination for preteen children and boosters for teenagers. Vaccination also is recommended for younger children and adults who might be at increased risk of meningitis for any of the following reasons:

  • Traveling to countries where meningitis is common.
  • Having an immune system disease called terminal complement deficiency.
  • Having a damaged spleen or having had the spleen removed.
  • Living in a college dormitory.
  • Joining the military.

Preparing for an appointment

The timing of diagnosing a child with hydrocephalus can depend on how bad the symptoms are and when problems appeared. It also may depend on whether there were risk factors for hydrocephalus during the pregnancy or delivery. Sometimes hydrocephalus can be diagnosed at birth or before birth.

Well-baby visits

It's important to take your child to all regularly scheduled well-baby visits. Health care professionals monitor your child's development in key areas, including:

  • Head size, rate of head growth and overall body growth.
  • Muscle strength and tone.
  • Coordination.
  • Posture.
  • Age-appropriate motor skills.
  • Sensory abilities such as vision, hearing and touch.

Questions you should be prepared to answer during regular checkups might include:

  • What concerns do you have about your child's growth or development?
  • How well does your child eat?
  • How does your child respond to touch?
  • Is your child reaching certain milestones in development, such as rolling over, pushing up, sitting up, crawling, walking or speaking?

Preparing for other health care visits

You'll likely start by seeing your child's or your health care professional. You may then be referred to a doctor who specializes in brain and nervous system conditions, known as a neurologist.

Be prepared to answer the following questions about your symptoms or on your child's behalf:

  • What symptoms have you noticed? When did they begin?
  • Have these symptoms changed over time?
  • Do these symptoms include nausea or vomiting?
  • Have you or your child had any vision problems?
  • Have you or your child had a headache or fever?
  • Have you noticed personality changes, including increased irritability?
  • Has your child's school performance changed?
  • Have you noticed new problems with movement or coordination?
  • Is your child having trouble sleeping or lacking in energy?
  • Has your infant had seizures?
  • Has your infant had problems with eating or breathing?
  • In older children and adults, have symptoms included loss of bladder control and urinating often?
  • Have you or your child had a recent head injury?
  • Have you or your child recently begun a new medicine?

Content From Mayo Clinic Updated: 09/14/2023
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