A specific cause of Multiple Sclerosis has not been determined to the moment, but there are several possible theories. MS is considered as an autoimmune disease in which the body’s immune system attacks normal body tissue. The cells that make myelin, myelin itself and/or the axons (the nerves) are attacked when MS occurs.

For a better understanding of the disease, knowledge of how the Immune System works is required.

The nervous system is one of the body’s systems that talks with other systems and to itself. Thus we have movement, sensations, reactions, etc. However, as already said, the nervous system is not the only system that communicates with other systems and itself. The immune system also does this, and, as it is well known, this body system is responsible for destroying foreign substances, like viruses and bacteria. While in the case of AIDS the immune system doesn’t act properly being virtually inactive, in the case of MS, the immune system is too active. This is why MS is considered an autoimmune disease.

There are a great number of things that influence one’s immune system, like exposure to foreign substances, stress but also, life itself. While one virus may turn the system off, another one may turn it on.

Another possible cause of MS might be genetic. Even if MS itself is not a hereditary disease, 10% to 20% of people suffering from it have MS cases in their extended families. This means that people don’t inherit MS, but rather a possibility of developing it. For people that have no cases of MS in their close family members the probability of developing the disease is 0.2%. If a parent has MS then there is a 2% chance to develop MS, while if an identical twin has MS there is a 30% chance to develop MS.

Of course, viruses may also stimulate the immune system and lead to the development of MS in the case of susceptible individuals (those that have an over-active immune system). However, up till this moment, no virus was isolated in persons suffering from MS.

Other factors that seem to be related to MS are one’s geographical localization of the globe. According to this, people that spend the first 15 years of life in areas at a distance from the Equator seem to have a higher risk for developing MS. After this period of time there isn’t any correlation between the location and MS, but is seems that Caucasians are predisposed to MS more than other races.