Skip to main content

Health condition · Clinically reviewed

Hydrocephalus, the ventricles, the pressure and the plan.

Not one condition but a family - congenital, obstructive, communicating and normal pressure. With modern imaging and neurosurgery the outlook is often very good.

Jump to treatment
A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against NICE, the Society of British Neurological Surgeons and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK neurosurgical practice including programmable shunts, ETV and NPH tap testing.

Key facts

Hydrocephalus at a glance.

The essentials, in plain English - what it is, the main types, and how it is treated in the UK today.

  • What it is

    Abnormal accumulation of cerebrospinal fluid inside the brain, expanding the ventricles and raising intracranial pressure.

  • Types

    Communicating, non-communicating (obstructive), congenital, acquired, normal pressure hydrocephalus and hydrocephalus ex-vacuo.

  • In children

    Often congenital or from prematurity - macrocephaly, bulging fontanelle and sunset eyes need urgent paediatric neurosurgery.

  • In adults

    Headache, vomiting, papilloedema and gait change - specialist neurology and neurosurgery input is standard.

  • Definitive care

    Ventriculoperitoneal shunt or endoscopic third ventriculostomy, chosen by cause and anatomy.

  • NPH

    A treatable adult syndrome - gait apraxia, cognitive change and urinary incontinence - specialist commissioned assessment matters.

Why this guide matters

One name, several very different conditions.

The word covers a spectrum - from a newborn with a bulging fontanelle to an older adult with a subtle gait change. The three points below shape the rest of the page.

  • Type dictates treatment

    Obstructive disease often suits endoscopic third ventriculostomy, while communicating hydrocephalus and NPH usually need a programmable shunt.

  • Imaging comes first

    CT and MRI show ventricle size and the underlying cause - specialist commissioned interpretation guides every next step.

  • NPH is often missed

    Gait, cognition and continence together in an older adult deserve a specialist commissioned tap test - some improve dramatically after shunting.

How the diagnosis is made

From first symptoms to a clear plan.

The steps a UK GP, neurologist or neurosurgeon will normally follow, in order - so you know what to expect and why.

  1. 01

    Assessing

    History and red flags

    Headache pattern, vomiting, gait change, cognitive slowing or - in infants - head-size trajectory and feeding.

  2. 02

    Assessing

    Neurological examination

    Fundoscopy for papilloedema, cranial nerves, gait, cognition and, in babies, fontanelle and sunset eyes.

  3. 03

    Assessing

    Same-day imaging

    CT brain to look for ventriculomegaly and acute causes - specialist commissioned as an emergency where indicated.

  4. 04

    Confirming

    MRI brain for anatomy and cause

    Higher resolution assessment for aqueductal stenosis, Chiari, tumour, colloid cyst or Dandy-Walker - specialist commissioned.

  5. 05

    Confirming

    Lumbar puncture, when safe

    Opening pressure and CSF studies where there is no obstructing lesion - avoided in obstructive disease because of herniation risk.

  6. 06

    Planning

    NPH tap test

    Large-volume LP with pre and post gait and cognition testing - improvement is predictive of shunt benefit and is specialist commissioned.

  7. 07

    Planning

    Neurosurgical MDT

    Neurosurgery, neurology, neuroradiology and, in children, paediatrics agree on shunt, ETV or treatment of the underlying cause.

Typical timeline: from first symptoms to a specialist commissioned plan in days to weeks.

Symptoms

What hydrocephalus actually looks like.

The pattern depends on age and cause - raised pressure signs in adults, macrocephaly in infants, and the NPH triad in older adults.

  • Headache and vomiting

    Classic raised-pressure headache - worse on waking or lying down, often with vomiting and see /conditions/headaches/ for context.

  • Papilloedema

    Swelling of the optic disc on fundoscopy - a hard sign of raised intracranial pressure and needs neurosurgical review.

  • Gait disturbance

    A magnetic, shuffling gait is a hallmark of normal pressure hydrocephalus and often improves after a tap test or shunt.

  • Cognitive change

    Slowed thinking, attention lapses or a subcortical-dementia picture that overlaps with dementia - see /conditions/dementia/.

  • Urinary incontinence

    Urgency then incontinence is the third leg of the NPH triad and often lags gait change by weeks or months.

  • Macrocephaly and bulging fontanelle

    In babies - a rapidly growing head or tense fontanelle needs same-day paediatric neurosurgery.

  • Sunset eyes and irritability

    Downward deviation of the eyes, poor feeding and irritability in an infant point to raised pressure.

  • Red flag - reduced consciousness

    Drowsiness, confusion or coma in a person with known hydrocephalus is a neurosurgical emergency.

Treatment

How hydrocephalus is treated in the UK.

Neurosurgery is the mainstay - shunts, ETV or treatment of the underlying cause - with programmable valves and specialist commissioned follow-up.

  • Ventriculoperitoneal shunt

    The definitive treatment for most patients - a programmable valve is placed by specialist commissioned neurosurgery and drains CSF from the ventricle to the peritoneum.

  • Endoscopic third ventriculostomy

    Preferred where feasible in obstructive, non-communicating hydrocephalus - a small opening in the third ventricle floor restores CSF flow without hardware.

  • Treat the underlying cause

    Resection of a tumour, colloid cyst or removing an obstructing lesion may resolve hydrocephalus without a permanent shunt.

  • External ventricular drain

    A temporary bedside drain used in acute or emergency hydrocephalus - a bridge to definitive surgery in a neurosurgical unit.

  • NPH shunt pathway

    Selected adults with the NPH triad benefit from a programmable VP shunt after a positive tap test, with dementia workup running alongside.

  • Programmable valve adjustment

    Non-invasive changes to shunt pressure settings tailor drainage to the individual and reduce over or under-drainage.

  • Management of complications

    Shunt infection, obstruction, over-drainage and subdural collections all need specialist commissioned neurosurgical review, often with revision.

  • MDT and support

    Neurosurgery, neurology, rehabilitation and charities such as Shine and the Neurological Alliance coordinate long-term care and follow-up.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP, neurologist or neurosurgeon knows your history and imaging and can tell you which parts apply to you. If in doubt, get seen.

  • NICE. Normal pressure hydrocephalus - interventional procedures guidance.

  • Society of British Neurological Surgeons (SBNS). Standards for hydrocephalus and shunt care.

  • British Paediatric Neurology Association. Paediatric hydrocephalus pathways.

  • Shine Charity. Patient guidance on hydrocephalus and spina bifida.

Red flags

When hydrocephalus needs urgent attention.

Some presentations belong in the emergency department, not the GP surgery. These are the ones to know.

  • Sudden reduced consciousness

    Drowsiness, confusion or coma in known hydrocephalus points to shunt failure or acute obstruction - a neurosurgical emergency.

  • Rapidly growing head in an infant

    Crossing centiles, bulging fontanelle or sunset eyes need same-day paediatric neurosurgery.

  • New severe headache with vomiting

    Thunderclap or persistent early-morning headache with vomiting warrants urgent imaging - see /conditions/subarachnoid-haemorrhage/.

  • Shunt-site swelling, redness or fever

    Suggests shunt infection - a surgical emergency with a low threshold for admission and CSF sampling.

  • Papilloedema on examination

    A hard sign of raised intracranial pressure that mandates neurosurgical review, whatever the presumed diagnosis.

  • Post-haemorrhage or post-meningitis decline

    A step down after SAH, IVH or meningitis - see /conditions/hemorrhagic-stroke/ - can signal communicating hydrocephalus.

  • Rapid gait and cognitive decline

    Weeks-to-months progression in an older adult may be NPH - a treatable cause worth flagging early.

  • Suspected colloid cyst

    Positional headaches with drop attacks in a young adult can indicate a colloid cyst obstructing the foramen of Monro.

  • Known Chiari or Dandy-Walker

    Existing posterior fossa anomalies raise the risk of obstructive hydrocephalus - see /conditions/chiari-malformation/.

Living with it

A treatable condition, with a clear plan.

Four things that make the biggest difference day to day - carrying your shunt details, knowing the warning signs, keeping follow-up and using the charities.

A quiet reminder

If a symptom you recognise comes back, get seen.

Shunt failure is treatable but time-critical - a same-day neurosurgical review is safer than waiting to see what happens.

  1. 01 Shunt card

    Carry your shunt details

    Valve type, settings and neurosurgical unit - useful in A&E and before any MRI, which can reprogramme some valves.

  2. 02 Warning signs

    Know what shunt failure looks like

    New headache, vomiting, drowsiness or the return of old symptoms deserves same-day neurosurgical review.

  3. 03 Follow-up

    Keep specialist reviews

    Regular neurosurgical and, where relevant, neurology follow-up catches over-drainage, obstruction and subdurals early.

  4. 04 Support

    Use the charities

    Shine and the Neurological Alliance offer practical, emotional and family support - not just information.

Frequently asked

Everything we get asked about hydrocephalus.

Quick answers on types, imaging, VP shunts, ETV and normal pressure hydrocephalus.

  • What is hydrocephalus?

    An abnormal build-up of cerebrospinal fluid inside the brain that expands the ventricles and raises intracranial pressure. Causes range from congenital malformations and prematurity to tumours, haemorrhage, meningitis and idiopathic normal pressure hydrocephalus in older adults.

  • What is the difference between communicating and non-communicating hydrocephalus?

    Communicating hydrocephalus is a problem of CSF absorption - after subarachnoid haemorrhage, meningitis or tumour, for example. Non-communicating or obstructive hydrocephalus is caused by a block along the CSF pathway, such as aqueductal stenosis, a colloid cyst, a tumour, or Chiari or Dandy-Walker malformations.

  • What is normal pressure hydrocephalus?

    A specific adult syndrome of gait apraxia, cognitive change and urinary incontinence with enlarged ventricles on imaging but normal opening pressure. Selected patients improve dramatically after a specialist commissioned tap test and a programmable ventriculoperitoneal shunt.

  • How is hydrocephalus diagnosed?

    History, neurological examination and imaging with CT and MRI. Lumbar puncture with opening pressure is used where safe - it is avoided in obstructive disease because of herniation risk. NPH assessment adds a large-volume tap test with gait and cognitive testing before and after.

  • What is the difference between a VP shunt and ETV?

    A ventriculoperitoneal shunt is a permanent programmable valve that drains CSF from a ventricle to the abdominal cavity. Endoscopic third ventriculostomy makes an opening in the floor of the third ventricle so CSF bypasses the block, avoiding hardware in the body. ETV is preferred in obstructive hydrocephalus where the anatomy allows it.

  • What can go wrong after a shunt?

    Shunt infection, obstruction, over-drainage and subdural collections are the main complications. Any new headache, vomiting, drowsiness or return of old symptoms needs same-day specialist commissioned neurosurgical review - shunt failure is treatable but time-critical.

Related content

Keep reading.

Pulse Healthcare concierge

Send us your enquiry

A concierge service for UK private healthcare. We match you with the best vetted clinics and consultants in our network - they then contact you directly.

So we can match you to the right clinician close to you.

We reply to every enquiry within 24 hours (Mon–Fri). Confidential - your details are never shared outside our vetted consultant network.