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PubMed This is a summary of 121 peer-reviewed journal articles Updated
Neurosurgery

Hydrocephalus: A Patient Guide

At a Glance

Hydrocephalus is a buildup of fluid in the brain’s chambers that can enlarge them and increase pressure on brain tissue. Symptoms vary by age and cause, and treatment may include a drainage shunt or an endoscopic bypass procedure followed by lifelong monitoring.

EMERGENCY NOTE: If you or a loved one experience sudden severe headache, repeated vomiting, declining alertness, new weakness, a seizure, or a bulging fontanelle (in infants), seek emergency care immediately. Non-emergency questions should be directed to your treating team.

Hydrocephalus is a condition characterized by the abnormal accumulation of cerebrospinal fluid (CSF) within the brain’s internal chambers, known as ventricles [1][2]. In a healthy system, this fluid cushions the brain and clears away waste before being absorbed back into the bloodstream. When this balance is disrupted—either because the fluid is blocked or because it isn’t being absorbed correctly—the ventricles enlarge and can put pressure on the delicate tissues of the brain [3][4].

The way hydrocephalus behaves depends heavily on the person’s age and the underlying cause. It occurs across the lifespan. In infants, whose skull bones have not yet fused, the condition often appears as a rapidly increasing head size or a bulging soft spot [5][6]. Older children and adults with acquired hydrocephalus (caused by trauma, tumors, or infection) more commonly experience symptoms of increased pressure, such as headaches, nausea, or changes in vision [6][7]. In older adults, a specific form called idiopathic normal-pressure hydrocephalus (iNPH) typically presents with a “triad” of symptoms: a shuffling or “magnetic” walk, urinary urgency, and cognitive changes [8][9].

It is critical to distinguish true hydrocephalus from a condition called hydrocephalus ex vacuo. While both involve large ventricles on an MRI, they have opposite causes. In hydrocephalus, the fluid itself is the problem, pushing the brain outward. In ex vacuo, the ventricles look large simply because the brain tissue around them has shrunk due to aging or dementia [3][10]. Identifying this difference is essential because surgery can often improve true hydrocephalus, but it cannot restore brain tissue lost to atrophy [11][12]. Keep in mind that these conditions can coexist; a finding of atrophy does not automatically rule out treatable hydrocephalus.

Standard treatments focus on restoring the brain’s fluid flow. A common approach is a ventriculoperitoneal (VP) shunt, a flexible tube that carries excess fluid from the brain to the abdomen [3][13]. An alternative for selected patients is Endoscopic Third Ventriculostomy (ETV), a procedure where a surgeon creates a small bypass in the brain to allow fluid to flow naturally without a permanent implant [14][15]. While these treatments help manage the condition, they require lifelong surveillance, as the bypass or device can occasionally fail even years after a successful surgery [16][17].

Navigating hydrocephalus is a journey of ongoing vigilance rather than a one-time fix. With regular follow-up care and a clear understanding of the condition’s symptoms, many people improve or maintain function with timely, appropriate treatment and support. However, individual prognosis depends on the cause, duration, baseline injury, and response to treatment.

In this guide

6 chapters

01

Understanding Hydrocephalus and How It Works

Learn how hydrocephalus disrupts brain fluid, how symptoms vary by age, and how doctors use scans and other tests to evaluate infants, adults, and older adults.

02

Subtypes of Hydrocephalus and Diagnostic Tests

Learn how hydrocephalus types are diagnosed, from obstructive and communicating forms to MRI, CT, tap tests, and external lumbar drainage for iNPH care.

03

Is it Hydrocephalus or Brain Shrinkage?

Learn how MRI clues and symptoms help distinguish idiopathic normal pressure hydrocephalus from hydrocephalus ex vacuo and understand when shunting may help.

04

Standard Treatment Options: Shunts and ETV

Learn how hydrocephalus is treated with VP shunts, ETV, and ETV+CPC, including age-based choices, programmable valves, MRI precautions, risks, and infant care.

05

Living with a Shunt or ETV: Warning Signs and When to Act

Learn hydrocephalus shunt and ETV warning signs, including emergency symptoms, infection, under- or over-drainage, and why scans may not rule out failure.

06

Living with Hydrocephalus: Long-Term Care and Quality of Life

Learn how long-term hydrocephalus care supports daily life, including follow-up, MRI or CT scans, therapy, sports, warning signs, and transition to adult care.

Common questions in this guide

When is hydrocephalus an emergency?
Seek emergency care for a sudden severe headache, repeated vomiting, worsening alertness, new weakness, or a seizure. In an infant, a rapidly enlarging head or bulging fontanelle, also called the soft spot, needs urgent medical assessment.
How can doctors tell hydrocephalus from hydrocephalus ex vacuo?
In true hydrocephalus, extra cerebrospinal fluid enlarges the brain’s ventricles and may press on brain tissue. In hydrocephalus ex vacuo, the ventricles appear large because surrounding brain tissue has shrunk, often with aging or dementia; the two conditions can occur together, so imaging and clinical assessment are important.
What is the difference between a VP shunt and ETV for hydrocephalus?
A VP shunt uses a tube to move extra fluid from the brain to the abdomen. ETV creates a small opening that lets fluid bypass a blockage without a permanent implant, and the preferred option depends on the cause and anatomy.
What symptoms can idiopathic normal-pressure hydrocephalus cause?
Idiopathic normal-pressure hydrocephalus, or iNPH, commonly causes a shuffling or magnetic walk, urinary urgency, and changes in thinking. These symptoms can have other causes, so a clinician must evaluate the full history and imaging before recommending treatment.
Will hydrocephalus treatment need follow-up for life?
Yes. Shunts and ETV require ongoing clinical follow-up and sometimes imaging because a device or bypass can stop working even years after surgery. Your treating team can set a monitoring schedule and explain which new symptoms should prompt a call.
What affects recovery from hydrocephalus?
Outlook depends on the cause, how long hydrocephalus has been present, any underlying brain injury, and how the person responds to treatment. With timely treatment, follow-up, and support, many people improve or maintain function, but individual outcomes vary.

Get notified when new evidence is published on Hydrocephalus.

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References

References (17)
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    Imaging Perspectives on Hydrocephalus: CSF Flow, Glymphatic Function, and Clinical Implications in the Diagnosis and Management of Normal Pressure Hydrocephalus.

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This hydrocephalus guide is for informational purposes only and does not constitute medical advice. A treating clinician should interpret symptoms and imaging and discuss whether a VP shunt or ETV is appropriate for your situation.