Each type of meningitis has a slightly different cause, but each ultimately acts in the same way: A bacterium, fungus, virus, or parasite spreads through the bloodstream until it reaches the brain, or spinal cord. There, it sets up in the lining or fluids around these vital body parts and starts developing into a more advanced infection.
Non-infectious meningitis is the result of a physical injury or other condition; it doesn’t involve an infection.