Normal Pressure Hydrocephalus

The ventricles are chambers in the brain that normally contain fluid. This fluid is called cerebrospinal fluid. Usually these chambers contain just the right amount of the fluid for normal brain function. Sometimes, however, too much fluid can build up in the ventricles. This accumulation of fluid leads to a condition called normal pressure hydrocephalus (NPH).

When excess fluid builds up, the ventricles enlarge and press against nearby brain tissue. This extra fluid can affect the shape of the brain and lead to brain damage. The condition, though rare, most often affects older adults, and its symptoms can be similar to those of Alzheimer's and Parkinson's diseases. A doctor familiar with these conditions can often tell the difference between these diseases and NPH after special testing. NPH may account for 5 percent of dementia cases in the U.S.

Facts about the disease

NPH can be caused by a number of underlying conditions, including brain infections, bleeding in the brain, tumors, and injuries. It can also occur for no clear reason.


These are possible symptoms of NPH:

  • Trouble walking

  • Poor balance

  • Falling

  • Changes in the way you walk

  • Forgetfulness

  • Mood changes

  • Depression

  • Difficulty responding to questions

  • Trouble with bladder or bowel control


Your medical team may need to do a number of tests to confirm NPH, such as:

  • Physical examination, which includes asking about your symptoms

  • Evaluation of the way you walk

  • CT or MRI scans of your brain

  • Spinal tap to remove a sample of your cerebrospinal fluid


A commonly used treatment for NPH is surgery to place a tube, called a shunt, into the brain to drain the excess fluid. The shunt is usually inserted into a ventricle in the brain and then passed under your skin from your head through your neck and chest to your abdomen. The extra fluid in your brain flows through the shunt into your abdomen, where your body absorbs it. The ventricles in your brain may then go back to their normal size.

Implanting a shunt doesn’t work for everyone, but some people do benefit from it. Getting prompt diagnosis and treatment helps improve your chances of a good outcome.


It's unknown whether people can do anything to prevent NPH.

Managing NPH

Shunt placement can lead to bleeding and infection, so it’s important that you and your family are aware of these possible complications. If you have this surgery, be sure to follow all of your doctor’s directions and keep any follow-up appointments to make sure it's working properly.