With multiple sclerosis, the central nervous system (CNS) is attacked by the person's own immune system. That is why MS is known as an auto-immune disease. Nerve fibers are surrounded by myelin, which protects them. Myelin also helps conduct electrical signals (impulses) - i.e. myelin facilitates a good flow of electricity along the nervous system from the brain. Myelin regulates a key protein involved in sending long-distant signals.

The myelin of a patient with MS disappears in multiple areas. This leaves a scar (sclerosis). Multiple sclerosis means "scar tissue in multiple areas." The areas where there is either not enough or no myelin are called plaques or lesions. As the lesions get worse the nerve fiber can break or become damaged. Symptoms of Multiple Sclerosis can be seen as follows:

tremor,
muscle spasticity,
incoordination of muscles,
painful involuntary muscle contractions,
slurred speech, and
fatigue.
visual changes including double vision or loss of vision
numbness,
tingling or weakness (weakness may range from mild to severe),
paralysis,
vertigo or dizziness,
erectile dysfunction (ED, impotence)
pregnancy problems,
incontinence (or conversely, urinary retention).