Intracranial hypertension

Intracranial hypertension (IH) is a build-up of pressure around the brain.

It can happen suddenly, for example, as the result of a severe head injury, stroke or ruptured brain aneurysm.

It can be caused by a condition that affects your brain, such as a brain abscess, brain tumour, meningitis or encephalitis.

IH can also develop as a complication of another condition such as high blood pressure.

Treatment for these types of IH depends on the cause.

Sometimes though there is no obvious reason why pressure builds up around the brain. Build-up of pressure with no known cause is known as idiopathic intracranial hypertension.

This page is about idiopathic intracranial hypertension.

Symptoms of intracranial hypertension

Symptoms of intracranial hypertension (IH) can include:

Immediate action required: Call 999 or go to A&E if you have any of these symptoms and:

  • they've come on quickly, such as a sudden severe headache, change in your vision, confusion or weakness
  • you've recently had a head injury
  • you have a high temperature, or you feel generally unwell

Diagnosing intracranial hypertension

A GP may suspect you have intracranial hypertension (IH) if you have symptoms of increased pressure on your brain, such as vision problems and headaches.

If a GP thinks you have IH they'll refer you to a hospital specialist.

You may have several different tests to diagnose IH, such as:

Idiopathic IH may be diagnosed if you have increased pressure on your brain and no other cause can be found.

Treatments for idiopathic intracranial hypertension

Treatments for idiopathic intracranial hypertension (IH) can include:


Surgery may be considered if other treatments do not help, particularly if your vision is getting worse or you're at risk of loss of vision.

The main types of surgery for idiopathic IH are:

These procedures can provide relief from your symptoms, but they also carry a risk of potentially serious complications. Talk to the surgeon about what your operation involves and what the risks are.

Risk factors for idiopathic intracranial hypertension

While the cause, or causes, of idiopathic IH is unknown, a number of risk factors have been linked to the condition.

It's a rare condition that mainly affects women in their 20s and 30s. It most often happens in women who have gained weight. The reason for this is unclear.

Other factors that have been linked with idiopathic IH include:

Complications of idiopathic intracranial hypertension

Idiopathic IH is not usually life threatening, but it can be a lifelong problem.

It can affect your vision, and there's a risk that you could lose your vision. This is because the increased pressure around the brain can cause swelling of the optic nerve.

Treatment can help with problems with your vision and can reduce the risk of loss of vision.

It's important to tell your doctor straight away if you notice any changes in your vision.

Find out more about living with idiopathic IH from the IIH UK website.

Page last reviewed: 28 March 2023
Next review due: 28 March 2026