If you know someone battling MS (Multiple Sclerosis), then you know the INTENSE amount of pain they can experience, and it comes on at the drop of a dime. One day they can feel good and their joints are those of a 20-year-old's, and the next day they just get walloped with pain and aches. According to the National Multiple Sclerosis Society, MS is "a chronic, inflammatory disease that involves immune-mediated attacks on the central nervous system." In lesser words, the disease basically just attacks you over and over (hence the above mention of being fine one minute and then in crippling pain the next), and in some cases, can render you disabled.