A disease in which the immune system eats away at the protective covering of nerves. In MS, resulting nerve damage disrupts communication between the brain and the body. Multiple sclerosis causes many different symptoms, including vision loss, pain, fatigue and impaired coordination. The symptoms, severity and duration can vary from person to person. Some people may be symptom free for most of their lives, while others can have severe, chronic symptoms that never go away. Physiotherapy and medication that suppress the immune system can help with symptoms, and slow disease progression.