Intracranial hypertension

Also called Idiopathic intracranial hypertension, IIH, or Pseudotumour cerebri

Intracranial hypertension is a build-up of pressure around the brain. It can come on suddenly because of a head injury, stroke or infection, or develop over time. When there is no obvious cause it is called idiopathic intracranial hypertension (IIH), which most often affects women of childbearing age who are overweight.

Last updated Nov 9, 2026

What it is

Raised pressure can cause swelling of the optic nerve and permanent sight loss if not treated.

Treatment for IIH includes weight loss, medicines to reduce fluid, and sometimes surgery or a shunt.

Common signs

  • Headaches, often worse when lying down
  • Blurred vision or brief loss of vision
  • Double vision
  • Whooshing sound in the ears
  • Feeling sick

How it is usually diagnosed

  • Eye examination for swelling of the optic nerve
  • Brain scan (MRI or CT)
  • Lumbar puncture to measure pressure

Records worth keeping

Keeping these together makes each appointment easier, especially when you see a new doctor:

  • Eye examination and visual field results
  • Brain scan reports
  • Lumbar puncture pressures
  • Neurology and eye clinic letters

Questions to ask your doctor

  • Is my eyesight at risk?
  • How often do my eyes need checking?
  • Would weight loss help?

When to get help right away

Call 112 or go to the nearest emergency department if you have:

  • Sudden severe headache, sudden loss of vision, or confusion: call 112

This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.

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