What Is Multiple Sclerosis?

MS is thought to be an autoimmune disease that affects the central nervous system (CNS). The CNS consists of the brain, spinal cord, and the optic nerves. Surrounding and protecting the nerve fibers of the CNS is a fatty tissue called myelin which helps nerve fibers conduct electrical impulses.

In MS, myelin is lost in multiple areas, leaving scar tissue called sclerosis. These damaged areas are also known as plaques or lesions. Sometimes the nerve fiber itself is damaged or broken.

Myelin not only protects nerve fibers, but makes their job possible. When myelin or the nerve fiber is destroyed or damaged, the ability of the nerves to conduct electrical impulses to and from the brain is disrupted, and this produces the various symptoms of MS.


Symptoms of MS

Symptoms of MS are unpredictable and vary from person to person and from time to time in the same person. For example, one person may experience abnormal fatigue, while another might have severe vision problems. A person with MS could have loss of balance and muscle coordination making walking difficult; another person with MS could have slurred speech, tremors, stiffness, and bladder problems. While some symptoms will come and go over the course of the disease, others may be more lasting.

Read more about the categories of symptoms or refer to the chart below for information on a specific symptom.

Most Common Symptoms
Symptom Description/Overview Management/Resources
Bladder Dysfunction Bladder Dysfunction

Personal Care: Bladder and Bowel Problems

Bowel Dysfunction Bowel Dysfunction
Changes in Cognitive Function, including problems with memory, attention, and problem-solving

Cognitive Function

MS and Cognition
Dizziness and Vertigo Dizziness and Vertigo
Depression and other Emotional Changes

Emotional Aspects


Emotional Aspects of MS

Depression and Multiple Sclerosis

Fatigue (also called MS lassitude)


MS and Fatigue
Difficulty in Walking and/or Balance or Coordination Problems


Gait or Walking Problems: The Basic Facts

MS and Mobility

Abnormal sensations such as Numbness or “pins and needles” Numbness


MS and Pain
Sexual Dysfunction Sexuality MS and Intimacy
Spasticity Spasticity Controlling Spasticity in MS
Vision Problems

Visual Symptoms

Optic Neuritis

MS and Vision