Meningitis is a potentially life-threatening infection of the meninges — the tough layer of tissue that surrounds the brain and the spinal cord. If not treated, meningitis can lead to brain swelling and cause permanent disability, coma, and even death.

Meningitis can be caused by a variety of things, including bacteria (the most serious), viruses, fungi, reactions to medications, and environmental toxins such as heavy metals. Although bacterial and fungal meningitis require extended hospitalization, meningitis caused by viruses can often be treated at home and has a much better outcome.