What is meningitis, and how do you catch it?  In order to understand this potentially deadly infection, let's first take a look at the structure of the central nervous system to understand what happens during meningitis and where.

What is meningitis?
The fluid that surrounds the brain and spinal cord is called cerebrospinal fluid. This fluid, CSF, protects the brain and can act as a shock absorber.  Cerebrospinal fluid is prevented from leaking by three different layers of thin tissue surrounding the brain, called the meninges (the brain coverings).  Therefore, meningitis is a medical term for inflammation of the meninges and CSF.

Meningitis can be caused by both bacteria or viruses.  To learn more about the types of meningitis and their causes, click here.  The next section reviews the causes of viral and bacterial meningitis here.