Hydrocephalus is a build-up of fluid in the brain. The excess fluid puts pressure on the brain, which can damage it.

If left untreated, hydrocephalus can be fatal.

Symptoms of hydrocephalus

The damage to the brain from hydrocephalus can cause a wide range of symptoms, including:

Different types of hydrocephalus can cause specific symptoms.

Read more about the symptoms of hydrocephalus.

Types of hydrocephalus

There are 3 main types of hydrocephalus:

Hydrocephalus present from birth

Congenital hydrocephalus is when a baby is born with excess fluid in their brain.

It can be caused by a condition such as spina bifida, or an infection the mother develops during pregnancy, such as mumps or rubella (German measles).

Many babies born with hydrocephalus (congenital hydrocephalus) have permanent brain damage.

This can cause several long-term complications, such as:

If your child has learning disabilities, they'll need extra support from their nursery or school to ensure their needs are being met.

Hydrocephalus that develops in children or adults

Acquired hydrocephalus can affect children or adults. It usually develops after an illness or injury.

For example, it may happen after a serious head injury or as a complication of a medical condition, such as a brain tumour.

Normal pressure hydrocephalus (NPH)

Normal pressure hydrocephalus (NPH) is an uncommon and poorly understood condition that most often affects people over the age of 60.

It can sometimes develop after an injury or a stroke, but in most cases the cause is unknown.

Mobility problems, dementia and urinary incontinence are the main symptoms of NPH. But because these symptoms happen gradually and are similar to those of other, more common conditions, such as Alzheimer's disease, NPH can be difficult to diagnose.

Diagnosing hydrocephalus

Brain scans, such as CT scans and MRI scans, can be used to diagnose congenital and acquired hydrocephalus.

A checklist is used to help diagnose NPH. For example, how you walk, your mental ability and symptoms that affect your bladder control will be assessed.

It's important to diagnose NPH correctly because, unlike Alzheimer’s disease, the symptoms can be relieved with treatment.

Read more about diagnosing hydrocephalus.

Treating hydrocephalus

Hydrocephalus can usually be treated using a thin tube (shunt) that's surgically implanted in the brain and drains away the excess fluid.

An endoscopic third ventriculostomy (ETV) can sometimes be used as an alternative to shunt surgery.

During this procedure, a hole is made in the floor of the brain to allow the trapped fluid to escape to the surface, where it can be absorbed.

Read more about how hydrocephalus is treated.

Complications after surgery

The surgery used to treat hydrocephalus can sometimes cause complications. For example, a shunt can become blocked or infected.

Before having surgery, your surgeon should discuss the possible complications with you.

Read more about the complications of surgery for hydrocephalus.

What causes hydrocephalus?

In the past, hydrocephalus was referred to as "water on the brain". However, the brain is not surrounded by water but by a fluid called cerebrospinal fluid (CSF).

CSF has 3 important functions:

The brain constantly produces new CSF (about a pint a day), while old fluid is released from the brain and absorbed into the blood vessels.

But if this process is interrupted, the amount of CSF can quickly build up, cause pressure in the brain.

Read more about the causes of hydrocephalus.

Help and support

If you have a child with hydrocephalus, or if you've been diagnosed with the condition yourself, you may find it helpful to speak to other people affected by hydrocephalus.

Shine, the spina bifida and hydrocephalus charity, can provide you with the details of local support groups and organisations.

You can find and contact your regional Shine team or read about support for carers on the Shine website.

Page last reviewed: 6 February 2023
Next review due: 6 February 2026