What Is Idiopathic Intracranial Hypertension?

Medically Reviewed by Poonam Sachdev on August 24, 2022
Written by Taylor Wendt
5 min read

Are you plagued by severe headaches that are getting worse over time? You might assume that you’re suffering from migraines, but then you start experiencing vision symptoms or even occasional blindness. 

If so, you might have a condition called pseudotumor cerebri or idiopathic intracranial hypertension (IIH). Learn more about the symptoms of this rare, hard-to-diagnose condition and understand how it can affect a person’s life. 

Idiopathic intracranial hypertension is caused by a buildup of cerebrospinal fluid (CSF) in the skull. Intracranial buildup of CSF can cause symptoms like pressure, pain, and vision changes over time. 

At first, you might not have any symptoms. Then, you may experience headaches. As the condition worsens, you might experience vision changes due to the CSF putting pressure on your optic nerve, which is responsible for your brain’s vision processing. 

Unfortunately, this condition's origin remains mysterious to doctors and researchers. The word “idiopathic” signifies that there is no obvious cause of this condition — or at least, not one that has been identified. 

This condition is also called “pseudotumor cerebri” because the symptoms of IIH can mimic those of a serious brain tumor. While IIH is not a brain tumor, it can cause serious symptoms, including vision loss, if it’s not treated in time.

While the root of IIH symptoms is the buildup of cerebrospinal fluid in a person’s brain, how and why this buildup happens is not entirely clear. 

If affected, you may experience the following symptoms:

  • An ache in the back of the head (this can be mild, moderate, or severe). It’s often worst first thing in the morning or late at night.
  • Vision changes such as blurred vision, double vision, or temporary blindness in one or both eyes.
  • Poor peripheral vision or blind spots.
  • Nausea and vomiting that can be confused with migraine symptoms.
  • Pain in your neck and shoulders.
  • A “whooshing” or “beating” sound like your heartbeat.
  • Ringing in your ears.
  • Progressive vision loss.

At first, it may be difficult to distinguish an IIH headache from a migraine. A migraine headache, though, is a condition that is often accompanied by an “aura,” or neurological changes, before the pain begins. For example, a person may see a light flashing, experience tingling in the fingers on one hand, or have trouble forming words.

Scientists understand more about migraines than IIH. Migraines involve specific nerves in the body that process pain (like the trigeminal nerve), and they are triggered by a number of environmental conditions like bright light, barometric pressure changes, hormones, and certain foods. The symptoms of IIH are not triggered by these factors, and they are caused by one factor only: a buildup of cerebrospinal fluid inside the skull.

IIH usually occurs in women of childbearing age who have a high body mass index and could be considered obese. In fact, about 90% of those diagnosed with IIH are obese. 

If no other cause is found for the person’s increased intracranial pressure, IIH can be diagnosed. It’s a diagnosis of exclusion, which means that other diagnoses must be considered first. It can only be diagnosed when the other options don’t fit.

This condition can progress over time, in which case it is considered chronic IIH — or it can hit abruptly, in which case it is considered acute IIH. Acute IIH might occur after a stroke or a car accident. If you have the acute subtype, you might notice many symptoms at the same time.

Chronic idiopathic intracranial hypertension stages may include headaches that get progressively worse over time. Your headaches might be accompanied by other symptoms such as temporary blindness, nausea, and dizziness. Finally, your vision will begin to deteriorate if you don’t seek treatment in time. 

It’s important to see a doctor if you have these symptoms, instead of trying to treat this condition by yourself, for this reason. 

Moderate weight loss. You might not conclude that a headache condition linked to intracranial pressure has anything to do with your weight — but it could. Weight loss is a first-line treatment for IIH. 

People who are very overweight or obese can alleviate some of these symptoms by losing 5 to 10% of their body weight. This isn’t drastic weight loss: For a person who weighs 200 pounds, this would be about 10 to 20 pounds, and for a person who weighs 300 pounds, this would be 15 to 30 pounds. 

Losing weight also decreases your risk for IIH in general. 

Your doctor might also ask you to follow a low-salt diet to prevent your body from retaining extra water. If you wish to lose more weight, or you’re not sure how to begin a low-salt diet, speak to a doctor or nutritionist.

Medication that lowers your CSF. If you are experiencing vision loss, your doctor might recommend that you take a medication called acetazolamide. This medicine is thought to help slow down the production of CSF in your brain and spinal cord, which will limit the buildup in your skull area.

Surgery. If you can’t take acetazolamide and your vision is getting worse, your doctor might refer you to a surgeon to discuss procedures referred to as “CSF diversion." These surgical procedures include the following options:

  • CSF shunting: You will be put under general anesthesia for this procedure. Your surgeon will use shunt tubing like a pipe to divert the cerebrospinal fluid to a different, non-threatening area of the body so that it does not build up in your brain.
  • Optic nerve sheath fenestration: For this procedure, the surgeon creates a fenestration, which is a tiny opening or series of slits created between the orbital cavity and the subarachnoid space in the back of the eye. The extra CSF causing the intracranial pressure is thus diverted into the orbital cavity.

Like migraine headaches, idiopathic intracranial hypertension can have a significant impact on your health and happiness. The difference is that IIH can be even more serious and can cause long-term health issues like vision loss. 

Remember that not all headaches with vision symptoms are migraines. While IIH is relatively rare, head pain with nausea and vision changes can be a sign of this serious condition. If you’re having severe headaches or symptoms that seem to be getting worse over time, don’t delay scheduling an appointment with your doctor.