What is multiple sclerosis (MS)? Symptoms, risk factors, types & treatment

Medical expert holding artificial human brain while standing at clinic

Multiple sclerosis (MS) affects more than 2 million people worldwide. It’s the most common chronic inflammatory disease of the central nervous system, yet most people don’t know much about it.

“Multiple sclerosis is such a complex disease,” says Dr. Suzanne Corrington, medical director at BlueCross BlueShield of Tennessee. “It’s extremely variable in how it affects different people who are diagnosed with it.”

What is multiple sclerosis?

“MS affects the central nervous system, which is made up of the brain, spinal cord and optic nerves,” says Dr. Corrington. “Those nerve cells coordinate activity in the body: moving, breathing, emotions, and so on. A protective coating (myelin) surrounds nerve cells, helping to transmit the signals properly.”

With MS, the body’s immune system has an abnormal response to myelin. Inflammation damages myelin as well as nerve fibers, which causes scar tissue to develop and harden (sclerosis). This makes it harder for nerve signals to get through.

“Because the central nervous system controls the whole body, the damage can occur in multiple places,” says Dr. Corrington, “and the resulting problems can vary from person to person, or even episode to episode.”

What are the symptoms of multiple sclerosis?

“It’s difficult to predict how MS will impact each person because there’s so much variation,” says Dr. Corrington.

Common symptoms include:

  • Vision problems
  • Weakness
  • Difficulty walking
  • Bladder problems
  • Pain

“All of these symptoms are more commonly caused by other medical problems rather than MS,” says Dr. Corrington. “So it’s easy to understand why MS may take years to diagnose, especially when many different symptoms come and go over time.”

Who is most likely to be affected by multiple sclerosis?

MS primarily affects younger adults, with the average age of onset being 30 years old. Women are affected 3 times more often than men.

Risk factors of MS are still unknown, though MS is believed to be caused by a combination of genetics and environmental factors.

What are the types of multiple sclerosis?

There are two primary categories, based on how the symptoms express themselves over time.

1. Relapsing MS (or relapsing-remitting)

Relapsing MS is the most common type, accounting for 90% of diagnoses. In it, clearly defined attacks (relapses) are followed by periods of partial or complete recovery (remissions). During remissions, some symptoms may disappear while others continue and become permanent; however, the disease doesn’t appear to progress during these periods.

2. Progressive MS

About 10% of people are diagnosed with progressive MS, which is characterized by worsening neurologic function without any relapses or remissions.

“There are also a number of subtypes within these categories, and some people will change from one category to another over time,” says Dr. Corrington. “Some people start out as relapsing-remitting and then change to progressive. It’s not clear cut.”

How do you treat multiple sclerosis?

“MS treatment is highly individualized and may change based on symptoms, response to treatment and side effects,” says Dr. Corrington. “Neurologists who routinely treat MS are skilled in diagnosing it, often using symptom history, an MRI and a neurological exam to make a determination.”

Once diagnosed, a treatment plan will be developed. Since there is currently no cure for MS, managing the condition is an ongoing process.

“Management can take many forms, such as medication, physical therapy and a healthy lifestyle (diet, exercise, sleep),” Dr. Corrington says. “Everyone has their own story and challenges. The important thing to know is that support is out there.”

Visit the National Multiple Sclerosis Society to learn more.

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Real story: Living with multiple sclerosis

Other articles from Dr. Corrington

Ashley Brantley

Ashley Brantley has been writing about food, culture and health for more than a decade, and has lived in three of Tennessee’s four major cities (Memphis, Nashville and Knoxville).

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Ashley Brantley has been writing about food, culture and health for more than a decade, and has lived in three of Tennessee’s four major cities (Memphis, Nashville and Knoxville).