Exactly what causes multiple sclerosis, otherwise known as MS, has yet to be determined. Researchers now believe that the two factors which have the most impact in whether a person develops multiple sclerosis are environment and genetics.

What Is MS?
Multiple sclerosis an autoimmune disease that affects the brain and spinal cord. As it progresses, the disease causes a loss of muscle control, vision, balance and sensation.

An autoimmune disease is a disorder in which the body's immune system, which normally protects against bacteria and viruses, mistakenly attacks normal, healthy tissues. With MS, the immune system attacks the central nervous system, specifically the nerves in the brain and spinal cord.

The body's nerves are covered with myelin, a fatty substance that insulates the nerves and prevents electrical nerve impulses from shooting off before they reach the brain. In a person with MS, this myelin coating is destroyed and replaced with scar tissue, a process known as demyelination. Without the myelin coating, nerve impulses disappear before they get to the brain or spinal cord. Scar tissue also blocks communication between the brain and the body by blocking nerve signals.

Why Does This Happen?
The exact reason why a body’s immune system turns on itself has not been determined. Genetics play a role, but not everyone with a family history of MS will wind up getting the disease. Environmental factors could also act as a trigger. Some studies have suggested that certain viruses, such as measles, herpes and flu viruses, may be associated with MS.

Occurrences of multiple sclerosis vary depending on where you live. MS is more common in Scotland, Scandinavia and northern Europe. For those living in the United States, MS affects whites more than any other racial group. Long-term studies show that if you relocate from an area with higher risk to one with lower risk, you acquire the risk of your new location, but only if you move before adolescence.

Research also indicates that MS may be hereditary. Close-degree relatives, those that are a first-, second- or third-degree relation to people with MS, have a higher risk of developing the disease. Those with sibling affected by MS have a 2% to 5% risk of developing MS.

Researchers believe that more than one gene is responsible for the predisposition to MS. Some scientists theorize that MS develops because a person is born with a genetic predisposition to react to some environmental agent. When that exposure occurs, an autoimmune response triggers.

What's the Prognosis of MS?
Researchers are still working to determine the underlying causes of MS and find a cure. Currently, MS is a degenerative disease with no known cure, which means that symptoms will get worse over time.

Early detection and treatment can make a big difference. Not every patient responds to treatment, but some treatments have slowed the progression of the disease and even reversed some symptoms. The body is capable of regenerating the myelin covering on nerve cells, but this happens very slowly. Some treatments aim to reduce the attacks on the myelin, giving the body a chance to heal.