Multiple sclerosis (MS) is a potentially disabling disease of the brain and spinal cord (central nervous system). In MS, the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems between your brain and the rest of your body. Eventually, the disease can cause permanent damage or deterioration of the nerves.
Signs and symptoms of MS vary widely and depend on the amount of nerve damage and which nerves are affected. Some people with severe MS may lose the ability to walk independently or at all, while others may experience long periods of remission without any new symptoms. While there is no cure for MS, treatments can help speed recovery from attacks, modify the course of the disease, and manage symptoms.
The National MS Society estimates that more than 2.3 million people have a diagnosis of MS worldwide and approximately 1 million people over the age of 18 in the United States have a diagnosis of MS.