What causes multiple sclerosis (MS)?
The cause of MS is still unknown, but most researchers think it results from an abnormal response by the body's immune system. Some researchers believe this abnormal immune response could be caused by a virus, although it is unlikely that there is just one virus responsible for triggering the condition. Researchers do know that MS is not contagious. And while it is not an inherited disease, genetic susceptibility plays a role. There is a higher risk for MS in families where it has already occurred. Other possible causes include environmental triggers such as exposure to toxins and heavy metals, as well as low levels of vitamin D.