What is the name of the condition where the immune system attacks the myelin sheath?

The condition where the immune system attacks the myelin sheath is multiple sclerosis. In MS, immune activity damages myelin, the fatty insulating material around nerve fibers in the brain and spinal cord. This disruption can slow or block nerve signals, producing symptoms such as vision problems, numbness, weakness, poor coordination, or fatigue.

The name refers to the multiple hardened scars, or scleroses, that can form in nervous tissue after repeated inflammation and demyelination. Early lesions may partially repair through remyelination, but repeated attacks can leave lasting plaques and damage the underlying axons. The exact cause remains uncertain, although genetic susceptibility and environmental factors both appear to contribute.

MS is often confused with amyotrophic lateral sclerosis because both conditions are shortened to ALS-related terms in casual discussion, but they are different diseases. Alzheimer’s disease primarily affects memory and cognition, while Parkinson’s disease chiefly involves movement and dopamine-producing nerve cells. MS specifically targets the central nervous system’s myelin and is commonly diagnosed between ages 20 and 40.