Understanding MS
Learning About MS
MS is a chronic disease that affects the central nervous system (CNS), which is made up of the brain, spinal cord, and nerve fibers to the eyes.
MS is widely thought to be an autoimmune disease, in which a mistaken immune response launches an attack on the body's own tissue. The destruction that results can disrupt the proper functioning of the CNS.
The CNS is made up mainly of nerve cells, which carry messages within the body. All the information sent to and from your brain and spinal cord is controlled by the CNS (Figure 1). MS puts these nerve cells and the messages they carry at risk. As a result, some people with MS may experience a decrease or loss of certain functions.
Nerves have a protective insulation around them, which is called myelin (Figure 2). Myelin helps ensure that messages are transmitted successfully.
- When myelin is damaged, it can cause scarring, or lesions, in the brain and the spinal cord (Figure 3).
- This damage can slow or block the nerve messages from traveling throughout your body (Figure 4).
- Some people with MS affected by this communication breakdown may experience a decrease or loss of certain functions.
MS symptoms show up differently depending on where nerve damage has occurred. For example, damage to one part of the brain may lead to difficulty thinking, whereas damage to another part of the brain may lead to a physical disability.
Silent damage can also occur. This is when damage is taking place, but no outward symptoms are present.
How many people have MS? And who gets it?
MS affects more than 2.5 million people worldwide.
Approximately 400,000 people have been diagnosed with MS in the US - with about 200 new cases diagnosed every week.
People with MS are generally between 20 and 40 years of age when they experience their first symptoms. However, initial symptoms can also appear earlier or later.
More than twice as many Caucasians develop MS compared to other races - and almost twice as many women are affected as men.
Types of MS 
