World Encephalitis Day will be observed on Monday, Feb. 22, which makes this a good time to learn more about this potentially life-threatening condition.
Encephalitis is inflammation of the brain. It affects nearly 500,000 people of all ages worldwide each year, according to the Encephalitis Society, with young children and older adults most vulnerable. Other risk factors include having a compromised immune system, living in certain areas of the world and the season of the year.
While the exact cause of encephalitis often is unknown, when a cause is known, it's most commonly a viral infection. Bacterial infections and noninfectious inflammatory conditions also can cause encephalitis. Autoimmune encephalitis, caused by the immune system attacking the brain, is similar in frequency to encephalitis from infections.
Encephalitis can injure the brain, possibly resulting in a coma or death. Other complications, such as fatigue, personality changes, paralysis and memory problems, may persist to varying degrees for months or be permanent.
Learn more about encephalitis and what you can do to keep yourself safe.