What is multiple sclerosis?

(CNN)Multiple sclerosis is a disease that affects the central nervous system and is considered an autoimmune disease, in which the immune system attacks its own healthy cells. It affects quality of life and can be disabling.

There is no cure for multiple sclerosis, which is often called MS, but many people are able to manage their symptoms and adapt to new lifestyles after diagnosis.

What causes multiple sclerosis?

The disease begins when a person's immune system attacks the coverings of nerve fibers throughout the body. These protective nerve sheaths are called myelin, and they assist with the communication of nerves.
    When myelin is destroyed, it exposes the nerves, slowing communication between these cells. The signs and symptoms are related to how much damage has been done. Researchers believe that the disease is the result of both environmental and genetic factors, but the underlying cause is not known.

    Whom does multiple sclerosis affect?

    There are several risk factors associated with multiple sclerosis that may put people at an increased risk, according to the National Library of Medicine.
    It more commonly occurs in Caucasian women between the ages of 20 and 40. Although multiple genes are suspected to play a role in the the risk of multiple sclerosis, the inheritance pattern is unknown.
    However, other factors can be changed to potentially reduce risk, such as quitting smoking and getting adequate levels of vitamin D. Studies show that smokers have 1.5 times the risk of developing multiple sclerosis than nonsmokers.

    What are the symptoms of multiple sclerosis?

    As the disease inflames the optic nerve, a condition known as optic neuritis, pain and loss of vision in the affected eye can result. This can be the first sign of multiple sclerosis, or it can show up later.
    Other symptoms include double vision, lethargy, loss of bladder and bowel function, muscle stiffness, numbness and weakness of the extremities, and depression. Another symptom is called Lhermitte's sign, an electric shock-like pain felt when the neck is moved.

    How is multiple sclerosis diagnosed?

    Multiple sclerosis is often diagnosed by ruling out other conditions; physicians are then able to form a differential diagnosis of what is causing the symptoms. An essential tool to diagnose the disease is magnetic resonance imaging or MRI testing, in which doctors look for bright white spots indicating disease activity in the brain and spinal cord. Doctors may also look at other related areas, like the optic nerve. A lumbar puncture, or spinal tap, may also be performed to look for abnormal proteins in the cerebrospinal fluid, called oligoclonal bands.
    The diagnosis is confirmed if a patient has damaged myelin in at least two areas of the central nervous system and has had at least two relapses, according to the American Academy of Family Physicians.

    What is the treatment for multiple sclerosis?

    During periods of acute worsening of symptoms, known as exacerbation or relapses, steroids can treat symptoms. Medications called disease-modifying therapies contribute to reducing both the number and severity of relapses.
    Muscle relaxants are usually prescribed to treat the stiffness that sometimes accompanies multiple sclerosis. Patients are monitored closely because of potential side effects from treatment, such as flu-like symptoms and injection site reactions.
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    The progression of the disease and medical management differ from patient to patient. Some people with multiple sclerosis may have longer periods of remission or periods of no disease symptoms; others may have a disease course so severe that they lose the ability to walk without assistance.
      While the disease can be life-altering, physical therapy and aids like canes and walkers can improve the ability to perform daily activities. There are also special considerations to prevent fatigue, including avoiding heat and excessive activity.
      Multiple sclerosis can be fatal, according to the National Institute of Neurological Disorders and Stroke. However, most patients are mildly affected, and life expectancy has improved in recent years.