Diagnosis

How is IIH diagnosed?

Tests usually include:

1. Eye tests, including visual fields, to check for blind spots and optic nerve swelling.
2. Brain imaging with MRI or CT to exclude other problems and look for features that fit with raised pressure.
3. Lumbar puncture (spinal tap) to measure CSF pressure and test the fluid.

Doctors use agreed criteria to make the diagnosis. These include symptoms of raised pressure, no other cause found on examination or scans, and raised CSF pressure on lumbar puncture.