Idiopathic intracranial hypertension (IIH) is increased pressure in your skull. It occurs because of cerebrospinal fluid (CSF) buildup around your brain. When CSF builds up in your skull, it can put pressure on your optic nerve, the nerve that helps you see. Symptoms of IIH might include vision changes, headaches or temporary blindness.
Idiopathic intracranial hypertension (IIH) is increased pressure around your brain. It occurs when cerebrospinal fluid (CSF), the liquid that cushions your spinal cord and brain, builds up in your skull. Pressure builds up in your brain and on your optic nerve, the nerve at the back of your eye that helps you see.
The word idiopathic means “no known cause.” Intracranial means “in the skull,” and hypertension means “high pressure.”
An outdated name for idiopathic intracranial pressure is pseudotumor cerebri. Pseudotumor cerebri means false brain tumor. IIH used to sometimes be called pseudotumor cerebri because the symptoms can be similar to brain tumor symptoms.
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Women are more likely to develop IIH than men. About 19 in 20 people with idiopathic intracranial hypertension are women. Most are between ages 20 and 50.
You are also more likely to have IIH if you have:
Overall, about 1 in every 100,000 people have idiopathic intracranial hypertension. In young females who have obesity, the rate is about 20 out of every 100,000.
Some intracranial hypertension occurs because of known causes. Some people have chronic (long-lasting) intracranial hypertension because of health conditions like brain tumors or blood clots.
Acute (sudden) intracranial hypertension can occur after a:
If you have idiopathic intracranial hypertension, that means CSF builds up for no known reason. This type can affect anyone but is most common in younger women who carry excess weight.
The most common sign of intracranial hypertension is a sudden, severe headache. Sometimes the headache is so painful that it wakes you from sleep. People with IIH may also have a change in vision. You might see double or have sudden blind spots. Several conditions can cause these symptoms, so check with your provider to find out if symptoms are related to IIH or another condition.
Intracranial hypertension symptoms can also include:
IIH used to be known as pseudotumor cerebri because the symptoms resembled symptoms of a brain tumor. Your provider may use several diagnostic tests to rule out a tumor and find the cause of your symptoms. You may have:
For most people, intracranial hypertension symptoms improve with treatment. Your provider may recommend:
If you have a condition that increases your risk of IIH, speak with your provider about how to best manage it. For example, if you have a high BMI, you can reduce your risk of IIH by losing weight. If you have iron-deficiency anemia, you may take iron supplements or other medications.
Without treatment, intracranial hypertension may lead to permanent vision loss. But most people find that treatment relieves intracranial hypertension symptoms. After treatment, you'll need regular checkups with an ophthalmologist (eye doctor) to monitor your vision.
Some conditions that affect your brain and spine may have similar symptoms to intracranial hypertension. These conditions include:
You may also want to ask your healthcare provider:
A note from Cleveland Clinic
Intracranial hypertension is increased pressure in your skull. It occurs because of CSF buildup. If you have idiopathic intracranial hypertension, it means healthcare providers don’t know what’s causing the fluid buildup. Intracranial hypertension can put pressure on your optic nerve. Symptoms often include severe headaches, blurred vision, blind spots or vision loss. If you have IIH, treatment might include weight loss, medications or surgery.
Last reviewed by a Cleveland Clinic medical professional on 10/18/2021.
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