Symptoms of any disease in the nervous system usually depend on which portion of the nervous system is involved. For example, a problem near the part of the brain involved with sensing movement will be felt as abnormal movement sensation or vertigo. A problem in the pathway carrying vision impulses will produce blurred vision. Trouble in the large bundle of nervous tissue in the neck (the spinal cord) will produce difficulties with sensation difficulties or trouble with the arms, legs, bladder, bowels, or sexual function. Some parts of the brain can be affected and cause few obvious symptoms. For example, the deep white matter of the brain can be affected and produce difficulty with concentration, finding words, or fatigue. Because people with MS have the disease for many years, they often experience similar symptoms as time goes by.

The most common symptom in MS is fatigue, usually excessive sleepiness and difficulty with concentration and energy in the middle and later parts of the day. After that sensation changes, as innocuous as tingling, shooting pains into the limbs, or as serious as constant pain in the head, trunk, or limbs which is difficult to relieve. Trouble with vision, such as blurred or double vision, which cannot be corrected with glasses. Difficulty walking, either to balance problems or leg weakness. Poor coordination or tremor of the hands. Vertigo, or an abnormal sensation of movement. These symptoms may come and go or persist depending on the individual. With time, these problems tend to be continuous. Many symptoms of MS worsen as the body temperature elevates from bathing, exercise, or even normal body temperature rises in the afternoon. Severe muscle stiffness or overactive reflexes may occur when the temperature is cooler.



Terms used to describe the course of MS refers to how the symptoms occur. "Relapsing" MS refers to individuals who experience well defined episodes of worsening symptoms, which may or may not completely resolve. Most people with MS begin with this pattern of illness. "Progressive" MS refers to worsening which is difficult to perceive, but noted usually over many months or years. This is not necessarily worse than the relapsing course, but it is more difficult to improve. After ten years of symptoms most MS will be classified as progressive. Generally, the older someone is, or if they are males, the less dramatic relapses.