• General population: approximately 1-3 per 100,000

• Obese women aged 15-44 years: up to 20-30 per 100,000 (Incidence may be increasing with rising obesity rates)

• IIH is less common in men, children and non-obese individuals

The exact cause of IIH remains unclear, but the condition involves impaired cerebral spinal fluid (CSF) absorption or increased CSF production, leading to increased intracranial pressure. Risk factors and associated conditions include:

• Obesity - the strongest risk factor, particularly in women;  adipose tissue may either produce direct mechanical pressure within the body, or contribute to hormonal or inflammatory imbalances

• Recent weight gain

• Medications - certain antibiotics (tetracyclines, minocycline), vitamin A derivatives (isotretinoin), growth hormone, corticosteroid withdrawal, lithium

• Endocrine disorders - polycystic ovary syndrome, thyroid disorders, Addison's disease

• Vitamin A excess

• Anemia

• Sleep apnea

• Venous sinus thrombosis (though this is considered secondary intracranial hypertension).

The hallmark symptoms of IIH result from increased intracranial pressure:

• Headaches - typically severe, daily, throbbing, worse in the morning or with position changes

• Visual disturbances - transient visual obscurations (brief episodes of vision loss lasting seconds), blurred vision, double vision (diplopia), peripheral vision loss

• Pulsatile tinnitus - whooshing sound in the ears that matches the heartbeat

• Neck or shoulder pain

• Nausea and vomiting

• Dizziness

• Vision loss - can be progressive and permanent if untreated

• Papilledema, bilateral swelling of the optic disc, is a common physical finding, resulting in pressure on the optic nerve and visual field loss.

The standard diagnostic framework for IIH is based on the Modified Dandy Criteria, for which all of the following should be met:

1. Signs and symptoms of increased intracranial pressure (such as headache, papilledema and transient visual obscurations (TVOs)).

2. No focal neurological deficits (except possible sixth cranial nerve palsy).

3. Normal brain imaging (no tumor, hydrocephalus, infection).

4. Elevated opening pressure on lumbar puncture (≥25 cm H₂O in adults) with normal cerebral spinal fluid composition.

5. No alternative cause identified for intracranial hypertension.

Additional testing may include visual field testing to assess peripheral vision loss and disease progression.

Treatment of IIH aims to preserve vision and alleviate symptoms. It may include the following:

Medical management:

• Weight loss - often the most effective intervention; 5-10% weight reduction can significantly improve symptoms

• Acetazolamide - a drug that inhibits the enzyme carbonic anhydrase involved in maintaining acid-base and fluid balance in the body and reduces CSF production

• Topiramate - a migraine headache medication with weight loss benefits

• Furosemide - a diuretic, sometimes used in addition to acetazolamide

• Serial lumbar punctures - temporary measure to remove CSF and reduce pressure.

Surgical interventions (for refractory cases or impending vision loss):

• Optic nerve sheath fenestration - creates opening in optic nerve sheath to relieve pressure on the nerve

• CSF shunting - ventriculoperitoneal or lumboperitoneal shunt to drain excess CSF

• Venous sinus stenting - for patients with venous sinus stenosis (narrowing).

A recent exciting development in IIH therapy is the emergence of GLP-1 receptor agonist weight loss drugs such as semaglutide and tirzepatide. These medications, already established for obesity and diabetes, appear to have broad beneficial effects for IIH. 

The prognosis for IIH is generally good with early intervention, but the condition is often chronic and prone to recurrence. Many patients respond well to weight loss and medical therapy with symptom improvement. Headaches often resolve with treatment. With early diagnosis, patients may maintain good vision, although some degree of permanent visual impairment may impact 10-25% of those with IIH. Recurrence is common, particularly with weight regain.

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2. Raoof, N., & Hoffmann, J. (2021). Diagnosis and treatment of idiopathic intracranial hypertension. Cephalalgia : an international journal of headache, 41(4), 472–478. https://doi.org/10.1177/0333102421997093.

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4. Chen, J., & Wall, M. (2014). Epidemiology and risk factors for idiopathic intracranial hypertension. International ophthalmology clinics, 54(1), 1–11. https://doi.org/10.1097/IIO.0b013e3182aabf11

5. Ognard, J., Alipour Khabir, S., Ghozy, S., El Hajj, G., Kallmes, K. M., Chen, J. J., Kadirvel, R., Kallmes, D. F., & Brinjikji, W. (2025). Use of glucagon-like peptide-1 receptor agonists in idiopathic intracranial hypertension : a systematic review. The journal of headache and pain, 26(1), 202. https://doi.org/10.1186/s10194-025-.

6. National organization for rare disorders (NORD):  Idiopathic intracranial hypertension.