context: Papilledema is swelling of your optic disc, the place where the nerve that goes to your brain connects inside your eye. This swelling is a reaction to a buildup of pressure in or around your brain. Often, it's a warning sign of a serious medical condition that needs attention. But sometimes the pressure and swelling can't be traced to a specific problem. In that case, there are other ways to ease the swelling. If you don't treat it, papilledema can lead to vision loss. Your brain's network of nerves, blood, and fluid all fit snugly inside your skull. Because there's a limited amount of space, when tissues swell, something grows, or there's more liquid than normal, the pressure inside goes up and, in turn, can cause papilledema. That may happen because of: A head injury A brain or spinal cord tumor Inflammation of the brain or any of its coverings, such as meningitis Extremely high blood pressure Bleeding in the brain A blood clot or a problem within certain veins Pus collecting from a brain infection Problems with the flow or amount of fluid that runs through the brain and spinal cord You can also get papilledema as a side effect of taking -- or stopping -- some medications, including: Corticosteroids Isotretinoin Lithium Tetracycline When there's no apparent reason for high pressure inside your skull, the condition is called idiopathic intracranial hypertension ( IIH). It happens to about 1 out of 100,000 people, but it's 20 times more likely among obese women in their childbearing years. As obesity rates rise, so does the IIH rate. Also, suddenly gaining an additional 5% to 15% of your body weight raises the odds, regardless of your starting weight. The exact link to being overweight isn't clear. It's possible that belly fat increases pressure in the chest and starts a chain reaction to the brain. You may not have any symptoms in the early stage of papilledema. Your doctor may discover it when they see optic disc swelling during a routine eye exam. As it progresses, you're likely to have vision problems, usually in both eyes. It's common to have blurred or double vision, and lose your vision for a few seconds at a time. Other symptoms are headache, queasiness, and throwing up. With IIH, some of these symptoms are more noticeable. You could get a headache every day and feel it on both sides of your head. The headaches may not always be the same intensity, but they do get worse as you keep getting them. You might hear throbbing in your head. Untreated papilledema can lead to serious eye problems, starting with the loss of your peripheral, or side, vision. In later stages, your vision can become completely blurred. Some people go blind in one or both eyes. Eye doctors use a tool called an ophthalmoscope to look inside the back of the eyes and diagnose papilledema. An imaging test, such as an MRI, can provide more details and possibly show what's causing the pressure in your brain. Later on, MRIs can measure how well treatment is working. Your doctor may want you to have a lumbar puncture, also known as a spinal tap. This test measures the pressure of the cerebrospinal fluid that runs through your brain and spinal cord. Further tests on a sample of this fluid can help diagnose an infection or tumor. If tests reveal a medical problem, treating it should cure papilledema as well. For instance, you might need antibiotics for a brain infection, surgery to drain an abscess or remove a tumor, or medicine to dissolve a blood clot. Your doctor may be able to switch a problem medication. Otherwise, your symptoms will likely guide your treatment. With slight papilledema and no symptoms, your doctor might simply keep checking you and do regular testing to spot any vision problems as soon as possible. For mild vision loss, treatment is usually to lose weight and take a diuretic (water pill) called acetazolamide. This drug helps bring down the pressure inside your head by lessening the amount of fluid in your body as well as the amount of fluid your brain makes. When you're overweight, losing just 5% to 10% of your body weight can improve symptoms and sometimes even cure papilledema. If you're having a hard time, ask your doctor if you might be a candidate for weight loss surgery. You can take a pain reliever for your headaches. Topiramate ( Topamax), used for migraines and seizures, also helps some people lose weight and lowers the pressure inside the skull. Removing some spinal fluid often eases the pressure and symptoms. Sometimes, just the fluid needed for testing is enough to make a difference. Or your doctor might want to do regular spinal taps to keep the pressure down. If your vision gets worse despite all these efforts, there are different types of brain surgery to relieve pressure and protect your optic nerve. Unless your doctor finds a specific cause and you treat it successfully, papilledema can return.