Intracranial hypertension (IH) is high pressure inside the skull, which may happen suddenly or build up gradually over time.
It's a relatively common condition with many different possible causes.
Acute IH occurs when the condition comes on rapidly as the result of a severe head injury, stroke or brain abscess, for example.
This page focuses on chronic IH, where the pressure inside the head has built up gradually over time. This is usually caused by an underlying disease, but sometimes there is no clear reason. It is often a severe, lifelong disease.
Chronic IH is often referred to as idiopathic intracranial hypertension – idiopathic means there is no known cause.
Some medical conditions, such as the following, can cause chronic IH:
Idiopathic IH means there is no obvious cause for the IH. It is most commonly seen in overweight women in their twenties.
Experts do not fully understand the link between excess weight and IH, and losing weight only sometimes helps symptoms.
Idiopathic IH is also associated with:
Note that these conditions are only linked with idiopathic IH; they are not necessarily causes.
Severe cases can lead to seizures, but most people with chronic IH generally experience:
You may also feel drowsy, confused and irritable, and have nausea and vomiting. Occasionally, you may hear a 'whooshing' sound in your ears.
IH may be suspected if you have signs and symptoms of increased intracranial pressure, such as vision problems and headaches.
A diagnosis of IH is made by ruling out other possible causes of the symptoms. The following should apply:
The treatment you have depends on the underlying condition causing your IH.
If you're overweight, it's important to lose weight. This often helps reduce eye symptoms and can sometimes relieve symptoms altogether without the need for medical treatment.
You may be given any of the following medicines to treat the underlying cause and help relieve symptoms:
The links above will take you to more information on these drugs, including their side effects.
You may need regular lumbar punctures to remove excess cerebrospinal fluid from your spine and skull, and to help keep down intracranial pressure. This procedure involves taking a sample of fluid from inside your lower back using a needle and syringe.
Surgery should be considered as a last resort if medication and weight loss fail to control your IH.
You may be offered shunt surgery, where a catheter (a thin, flexible tube) is inserted into the fluid-filled space in your brain or spine to divert the excess fluid to another part of the body.
The main types of shunt surgery are:
For many, shunt surgery provides long-term relief from symptoms, although there is a small risk of complications such as infection and blockage which you should discuss with your surgeon.
Rarely, if your vision is affected you may need to have a procedure called optic nerve sheath fenestration (ONSF). The surgeon will slit open the sheath surrounding your optic nerve to relieve the pressure on the nerve and allow the build-up of fluid to escape.
ONSF is very effective at relieving this nerve pressure and helping to treat problems with vision, but the amount of fluid removed is so small that it will not make a difference to the overall high pressure inside your skull and can lead to complications that include blindness. Again, your surgeon will explain all of these risks to you if you're considering this operation.
Chronic IH is not usually fatal, but treatment can result in serious, sometimes life-threatening complications.
Many patients with chronic IH find that their symptoms are relieved after treatment, although attacks of symptoms can recur.
Chronic IH is a life-changing condition and your intracranial pressure will need to be continuously monitored throughout the rest of your life.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.