Multiple Sclerosis (MS)

What is multiple sclerosis?

Multiple sclerosis (MS) is a long-lasting (chronic) disease of the central nervous system. It is thought to be an autoimmune disorder, a condition in which the body attacks itself by mistake. MS is an unpredictable disease that affects people differently. Some people with MS may have only mild symptoms. Others may lose their ability to see clearly, write, speak, or walk when communication between the brain and other parts of the body becomes disrupted.


Myelin is the fatty tissue that surrounds and protects nerve fibers. In MS, the myelin is destroyed in many areas. This loss of myelin forms scar tissue called sclerosis. These areas are also called plaques or lesions. When the nerves are damaged in this way, they can’t conduct electrical impulses to and from the brain.

What causes multiple sclerosis?

There are many possible causes of MS, such as:

  • Autoimmune disorders
  • Infectious agents, such as viruses
  • Environmental factors
  • Genetic factors

What are the symptoms of multiple sclerosis?

The symptoms of MS are often unpredictable. They may be mild or severe, short-term or long-lasting. They may appear in different combinations, depending on the area of the nervous system affected. The following are the most common symptoms of MS. But each person may have different symptoms.

First symptoms of MS

  • Blurred or double vision
  • Red-green color distortion
  • Pain and loss of vision because of swelling of the optic nerve (optic neuritis)
  • Trouble walking
  • An abnormal feeling, such as numbness, prickling, or pins and needles (paresthesia)

Other symptoms of multiple sclerosis

  • Muscle weakness in the arms and legs
  • Trouble with coordination. You may have problems walking or standing. You may also be partly or completely paralyzed.
  • Spasticity. This is the involuntary increased tone of muscles leading to stiffness and spasms.
  • Fatigue. This may be brought on by physical activity. But it may ease with rest. You may have constant tiredness that doesn’t go away.
  • Loss of feeling
  • Speech problems
  • Tremor
  • Dizziness
  • Hearing loss
  • Bowel and bladder problems
  • Depression
  • Changes in sexual function

About 50% of all people with MS have thinking (cognitive) problems linked to the disease. The effects of these problems may be mild. Your healthcare provider may only find them after much testing. The problems may be with:

  • Focusing (concentration)
  • Attention
  • Memory
  • Poor judgment

Symptoms of MS are grouped as primary, secondary, or tertiary as described below:

Primary symptoms. These symptoms are a direct result of the destruction of myelin:

  • Weakness
  • Numbness
  • Shaking (tremors)
  • Loss of vision
  • Pain
  • Paralysis
  • Loss of balance
  • Bladder and bowel problems

Secondary symptoms. These are complications that may occur as a result of the primary symptoms, for example:

  • Paralysis can lead to bedsores.
  • Bladder problems may cause repeated urinary tract infections.
  • Inactivity can result in weakness, poor posture, muscle imbalances, decreased bone density, and breathing problems.
  • Becoming less mobile because of weakness and trouble swallowing can lead to a greater risk of pneumonia.

Tertiary symptoms. These are social, job-related, and psychological problems:

  • A person who becomes unable to walk or drive may lose his or her livelihood.
  • Strain of dealing with a chronic illness may disrupt personal relationships.
  • Depression is often seen among people with MS.

The symptoms of MS may look like other health problems. Always talk with your healthcare provider for a diagnosis.

How is multiple sclerosis diagnosed?

Not one specific test is used to diagnose MS. Diagnosis is based on symptoms and signs, imaging tests, and lab tests. A healthcare provider can make a diagnosis by following a careful process to rule out other causes and diseases. Two things must be true to make a diagnosis of MS:

  1. You must have had 2 attacks at least 1 month apart. An attack is when any MS symptoms show up suddenly. Or when any MS symptoms get worse for at least 24 hours.
  2. You must have more than 1 area of damage to the central nervous system myelin. Myelin is the sheath that surrounds and protects nerve fibers. This damage must have occurred at more than 1 point in time and not have been caused by any other disease.

Your healthcare provider will ask about your health history and do a neurological exam. This includes:

  • Mental functions
  • Emotional functions
  • Language functions
  • Movement and coordination
  • Vision
  • Balance
  • Functions of the 5 senses

You may also need:

  • MRI. This diagnostic test uses a combination of large magnets, sound waves, and a computer to make detailed pictures of organs and structures within the body. It can find plaques or scarring caused by MS. Generally, a single attack along with certain patterns of changes in brain tissue seen on an MRI scan of the brain done with contrast can mean that you have MS.
  • Evoked potentials. These tests record the brain’s electrical response to visual, auditory, and sensory stimuli. These tests show if you have a slowing of messages in the different parts of the brain.
  • Cerebrospinal fluid analysis. This is also called a spinal tap or lumbar puncture. It looks at the fluid taken from the spinal column to make an evaluation or diagnosis. This test checks for cellular and chemical abnormalities seen with MS.
  • Blood tests. These are done to rule out other causes for various neurological symptoms.
  • Eye exam and visual fields measurements.