This document discusses multiple sclerosis, a disease that affects the central nervous system by causing the body's immune system to attack the protective myelin sheath covering nerve fibers in the brain and spinal cord. It can cause issues with vision, muscle control, balance and other functions. The document covers the types of MS, causes, risk factors, symptoms, and methods of diagnosis, including MRI scans and spinal taps to check for biomarkers of the disease in the cerebrospinal fluid.