Multiple sclerosis (MS) is a nervous system disease that affects your brain and spinal cord. It damages the myelin sheath, the material that surrounds and protects your nerve cells. This damage slows down or blocks messages between your brain and your body, leading to the symptoms of MS. They can include

• Visual disturbances
• Muscle weakness
• Trouble with coordination and balance
• Sensations such as numbness, prickling, or "pins and needles"
• Thinking and memory problems

No one knows what causes MS. It may be an autoimmune disease, which happens when your body attacks itself. Multiple sclerosis affects women more than men. It often begins between the ages of 20 and 40. Usually, the disease is mild, but some people lose the ability to write, speak or walk. There is no cure for MS, but medicines may slow it down and help control symptoms. Physical and occupational therapy may also help.