Multiple Sclerosis

What is multiple sclerosis?

Multiple sclerosis (MS) is an autoimmune disease that affects the nervous system. Normally, antibodies produced by the immune system help protect the body against viruses, bacteria and other foreign substances. In people who have MS, the immune system destroys the substance that surrounds and protects your nerve cells – the myelin sheath.

The job of the nervous system is to send electrical messages back and forth from the brain to different parts of the body. Normally, the brain quickly sends signals through the spinal cord and then through nerves that branch out to all organs and body parts. When myelin around nerves is damaged or destroyed, the nerves can’t function properly to deliver these signals in the right way. This can cause symptoms throughout the body.

Who gets MS?

MS affects women more than twice as often as men. White (Caucasian) people are more likely to develop it than people of other races. If someone in your family--such as a parent or sibling--has MS, you have a greater risk of developing it, too. MS can affect people of any age, but it often begins between the ages of 20 and 40. If you have another autoimmune disease, such as thyroid disease or Type 1 diabetes, your risk of developing MS is slightly higher.

Some studies show that where you live can affect your risk of getting MS. People who spend their childhood in areas with a temperate climate, such as northern United States or southern Canada, seem to be at higher risk for MS.

What causes MS?

No one really knows for sure what causes MS. It’s most likely the result of a combination of environmental, viral and genetic factors. A number of different viruses have been linked to MS. A childhood virus may trigger MS later in life.

What are the symptoms of multiple sclerosis?

MS affects normal sensation, thinking and movement. Symptoms vary from person to person, depending on the area of the body where the myelin sheath is damaged. Symptoms of MS may come and go. Flare-ups may last for days, weeks or months. After an episode, your symptoms may disappear for a while (go into remission), but scars can form and permanently affect nerves in that area.

Common symptoms include:
  • Vision problems, including double vision, blurriness, partial color blindness, eye pain, partial or complete loss of vision in 1 eye
  • Thinking and memory problems
  • Fatigue
  • Muscle weakness, dizziness or tremor
  • Numbness or weakness on one side or the bottom half of your body
  • Trouble with coordination and balance
  • Loss of bowel or bladder control
  • Sensations such as numbness or tingling, "pins and needles"
  • Electric-shock sensations caused by moving your head in a certain way

How do I know if I have MS?

There is no one test to tell if you have MS. Like other autoimmune diseases, MS may be difficult to diagnose. Often, the first symptoms of MS affect the eyes, causing blurred or double vision, or red-green color distortion. However, symptoms can also affect different parts of the body. Your doctor will ask you about your medical history, and use several strategies to determine if you have MS. Before making a diagnosis, your doctor will rule out other possible causes of your symptoms.

Your doctor may also order tests:

Blood test. Your blood can show signs of other illnesses that cause symptoms similar to the symptoms of MS.

Neurological tests. Your doctor may want you to see a neurologist who can test how well your nervous system is working. The tests will look for changes in eye movements, muscle coordination, weakness, balance, sensation, speech, and reflexes.

Spinal tap (lumbar puncture). A small amount of fluid taken from your spine can show abnormal amounts of blood cells or proteins associated with MS. A spinal tap can also rule out a viral infection or other possible conditions.

Magnetic Resonance Imaging (MRI). An MRI can show detailed pictures of the brain and spinal cord, and if there are any lesions present. However, lesions aren’t always caused by MS.

How is MS treated?

There is no cure for MS, but treatment can manage your symptoms. A combination of medicines, physical, speech and occupational therapies may help relieve your symptoms and maintain a good quality of life. Healthy nutrition, exercise and rest can also help make you feel better. You and your doctor will work together to develop a treatment plan that is right for you.

What can I expect?

The most common form of MS is known as relapsing-remitting MS (RRMS). When people who have this kind of MS have flare-ups, the symptoms become noticeably worse. Then there is a period of recovery, when symptoms get better or disappear completely for some time. In RRMS, symptom flare-ups may be triggered by an infection, such as the flu. More than 50% of people who have RRMS develop the secondary progressive type in which there are relapses followed by a gradual worsening of the disease.

About 15% to 20% of people who have MS have a form known as primary-progressive MS (PPMS). In this kind of MS, the disease gets steadily worse, without any remissions. A fourth type—progressive relapsing MS—is rare, but the pattern follows a worsening of the disease with sudden, clear relapses.

Often MS is mild, but some people lose the ability to write, speak or walk.
This information was developed as part of an educational program made possible through support from AstraZeneca.

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Written by editorial staff.

American Academy of Family Physicians

Created: 04/10