Multiple Sclerosis (MS) is caused by damage to the myelin sheath, the protective covering surrounding nerve cells. Damage to this sheath causes nerve impulses to slow down or stop. MS affects more women than men, and is most commonly diagnosed between the ages of 20 and 40 years, but MS can appear at any age.
Inflammation causes the nerve damage, which is a reaction to the body’s immune cells attacking the nervous system. The cause of the inflammation is unknown—some theories suggest a virus, genetic defect, or a combination. Some studies indicate that an environmental factor may be involved. Those with a family history of MS or who live in a geographic area where MS is more common have a slightly higher risk of getting the disease.