What Hydrocephalus Is in Adults

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Your brain floats in a clear fluid called cerebrospinal fluid, which is constantly made, circulated and absorbed. Hydrocephalus happens when that balance is upset and fluid builds up in the brain's fluid spaces, the ventricles, causing them to enlarge and press on the surrounding brain.

In adults, the form that matters most is normal pressure hydrocephalus, or NPH. The name is a little misleading — fluid still builds up, but the pressure reading can look normal, which is part of why it slips past so many people. It mostly affects people in their later years.

Adults can also develop hydrocephalus for other reasons — after a bleed, an infection, or a blockage to the fluid's flow. The symptoms and the urgency depend on the cause, but the unifying problem is the same: too much fluid, with nowhere to go.

The Three Tell-Tale Symptoms

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Normal pressure hydrocephalus has a classic trio of symptoms. They usually come on gradually, and walking trouble is often the first and most noticeable.

• Difficulty walking. A slow, shuffling, unsteady gait — feet feeling stuck to the floor, trouble starting to walk or turning. This is usually the most prominent sign.
• Thinking and memory changes. Slowed thinking, forgetfulness and difficulty concentrating — the part that most resembles dementia.
• Bladder problems. A frequent urge to pass urine, and later difficulty controlling it.

Not everyone has all three, and the walking difficulty tends to respond best to treatment. Because that gait change is so central, it's an important clue that separates NPH from other conditions that affect memory alone.

Why It's So Often Missed

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This is the heart of why this condition is worth knowing about. The slowed thinking and memory loss look so much like Alzheimer's, and the shuffling walk so much like Parkinson's, that NPH is frequently labelled as one of those — and then treated as untreatable.

The difference is enormous. Alzheimer's and Parkinson's can be managed but not cured. NPH, by contrast, is one of the few causes of these symptoms that can genuinely be treated, with many people improving after a straightforward operation.

That's why, when an older person develops this particular combination — especially the walking difficulty alongside memory change — it's so worth asking the question: could this be NPH? A brain scan and a specialist opinion can answer it, and the cost of missing it is years of decline that might have been avoided.

How It's Diagnosed

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Diagnosis starts with the symptoms and a brain scan — an MRI or CT — which shows the enlarged fluid spaces. But the most useful step is often a simple test that also predicts whether treatment will help.

In this test, a small amount of the cerebrospinal fluid is drained off, and the person's walking is checked before and after. If their gait visibly improves once some fluid is removed, it's a strong sign that a shunt — which does the same thing permanently — is likely to help them too.

This is reassuring, because it means the decision to treat isn't a guess. There's a way to gauge, in advance, who is most likely to benefit.

How It's Treated

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The aim of treatment is simple: drain the excess fluid so it stops pressing on the brain. There are two main ways to do this, depending on the type of hydrocephalus.

For NPH, the shunt is the standard treatment. It's a thin tube, placed under the skin, that quietly drains the surplus fluid away to the abdomen. Modern shunts often have an adjustable valve, so the drainage can be fine-tuned afterwards without further surgery.

Shunts are among the most established procedures in neurosurgery, used for both children and adults — the same principle covered for younger patients in the guide on paediatric neurosurgery in India. As with any brain procedure, the experience of the team matters, which is the focus of the guide to the best neurosurgeon in India.

Frequently Asked Questions

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What is hydrocephalus in adults?

Hydrocephalus is a buildup of cerebrospinal fluid in the brain's fluid spaces, causing them to enlarge and press on the brain. In adults it can follow a bleed, infection or blockage, but the most important form to recognise is normal pressure hydrocephalus (NPH), which mainly affects older people and is often treatable.

What is normal pressure hydrocephalus?

Normal pressure hydrocephalus is a form of hydrocephalus in older adults where fluid builds up even though the pressure reading can look normal. It causes a classic trio of walking difficulty, thinking and memory problems, and bladder symptoms. Crucially, unlike most causes of these symptoms, NPH can often be treated, with many people improving after a shunt operation.

What are the symptoms?

The three tell-tale symptoms are difficulty walking (a slow, shuffling, unsteady gait, often the first and most prominent), slowed thinking and memory problems, and bladder symptoms such as urgency and later difficulty with control. Not everyone has all three, and they usually come on gradually. The walking difficulty is both the most noticeable and the one that tends to respond best to treatment.

How is it treated?

The aim is to drain the excess fluid. The usual treatment is a shunt — a thin tube placed under the skin that drains surplus fluid from the brain to the abdomen, where the body absorbs it, often with an adjustable valve. For certain blocked types of hydrocephalus, a keyhole procedure called endoscopic third ventriculostomy creates a new internal drainage path instead.

Can a shunt reverse it?

For many people with NPH, yes — a shunt can lead to real improvement, especially in walking, and often in thinking and bladder symptoms too. Not everyone responds, which is why a simple test that drains a little fluid and checks whether the gait improves is so useful: it helps predict, in advance, who is most likely to benefit from a shunt.

Is NPH a form of dementia?

No, and this is the vital distinction. NPH causes memory and thinking problems that look like dementia, and it is frequently mistaken for Alzheimer's or Parkinson's. But unlike those conditions, NPH can often be treated and sometimes substantially reversed. That's why it's so important to consider NPH when an older person develops walking difficulty alongside memory change, rather than assuming untreatable dementia.