Optic neuritis
This is an inflammation of the optic nerve, the nerve that controls the eye. Over a period of days, your loved one may develop blurred vision or pain behind the eye, which increases when looking to the side. After initial symptoms, there is gradual improvement, sometimes after several weeks. But recovery is not always complete. During periods of stress, fatigue or fever, the blurred vision in the eye may return. This does not necessarily mean that the multiple sclerosis is active again. Rather, it may be the result of permanent disability that has accumulated over time.

Loss of muscle strength in arms and legs
The nervous system contains large numbers of nerve fibers that control movement - what we call motor function. Often, multiple sclerosis is active on the nerve fibers that control muscle movement. Many people with multiple sclerosis lose muscular strength in the arms and legs as the disease progresses. The loss can range from reduced dexterity (the fingers no longer work so well) to paralysis of an arm or leg. Loss of muscular strength occurs not only in the form of flare-ups (relapses or temporary attacks) but also as a gradual (progressive) process without recovery. Gradual loss of strength occurs more frequently in the legs than in the arms. Depending on the severity, your loved one may need to rely on a cane, crutches, or even a wheelchair to get around.

Change in sense of touch
The vast nervous system includes many sensory nerve fibers dedicated to helping you be aware of your environment. They provide the sense of touch in the fingers, and the ability to feel cold or heat on all parts of the body. When these fibers are damaged through multiple sclerosis, a person's sense of touch may be replaced by feelings of numbness or tingling. Parts of the body may feel burning or cold, even though there is no heat or chill present. Symptoms can be temporary (flare-ups or relapses) or more progressive, and can occur in various parts of the body. This could be just one part of an arm or leg, in the whole lower half of the body, say below the navel, or in a collection of numb patches occurring randomly all over the body. People may accidentally burn themselves frequently because they have a reduced ability to feel heat. Caregivers should be attentive to their loved ones who experience numbness to be sure they don't hurt themselves.

Pain
Multiple sclerosis can be accompanied by various kinds of pain. Damage to the sensory tracts in the spinal cord can result in burning pain in the arms and legs. Multiple sclerosis can often result in damage to the nerves of the face, a painful condition known as "trigeminal neuralgia." If multiple sclerosis has impaired your loved one's ability to walk, the extra strain in the muscles of the back and legs can become painful. Multiple sclerosis can also cause extra tension in the muscles of the arms and legs: this is known as "spasticity" and can also be painful.

Bladder/bowel problems
Many people with multiple sclerosis will develop trouble controlling the urge to urinate or will be unable to completely empty the bladder. Less frequently, they will also experience problems with bowel control. As multiple sclerosis progresses and your loved one develops a more sedentary lifestyle, he or she may also be troubled with constipation.

Sexual dysfunction
Having multiple sclerosis can lead to problems related to sexual activity, especially if the bladder or bowels are already affected. Men with multiple sclerosis can find it difficult to achieve or maintain an erection. In women, multiple sclerosis often causes a loss of sexual sensitivity, pain during intercourse, an inability to achieve an orgasm, or a reduction in naturally produced lubrication.

Balance/coordination problems
The part of the brain known as the cerebellum controls and corrects all our movements. Damage from MS can result in poor balance or coordination. Your loved one may, for instance, have difficulty grasping small objects, writing clearly, or keeping a steady hand. When walking across a room, your loved one may lose balance, as if he or she were intoxicated. Like most other multiple sclerosis symptoms, these problems can be temporary (during a flare-up or relapse), or they can be a permanent result of the progression of multiple sclerosis.

Fatigue
Many people with multiple sclerosis experience fatigue or tiredness. But since fatigue can be a sign of so many other diseases, too, it is not often immediately identified as being caused by multiple sclerosis. Fatigue occurs in both relapsing multiple sclerosis and in the more progressive types of the disease. It can often last for a few months during which time energy is used up every day with just a little exertion.

Changes in cognitive function
At some point in the course of multiple sclerosis, you may notice changes in your loved one's cognitive function, such as with memory and speed of thinking. Your loved one may also have difficulty concentrating and focusing. In some patients these symptoms can occur early in the disease; in others, they can come later. Caregivers may notice this symptom more readily than the person with multiple sclerosis. It's important to recognize that forgetfulness and difficulty concentrating are aspects of the disease and not due to lack of interest or willingness.