Disorders characterized by an abnormal reduction in muscle volume due to a decrease in the size or number of muscle fibers. Atrophy may result from diseases intrinsic to muscle tissue (e.g., MUSCULAR DYSTROPHY) or secondary to PERIPHERAL NERVOUS SYSTEM DISEASES that impair innervation to muscle tissue (e.g., MUSCULAR ATROPHY, SPINAL).

Synonyms: Disorders, Atrophic Muscular, Disuse Atrophies, Atrophies, Disuse, Muscular Disorders, Atrophic, Atrophic Muscular Disorders, Disorder, Atrophic Muscular, Atrophy, Disuse, Atrophic Muscular Disorder, Muscular Disorder, Atrophic, Spinopontine Atrophy, Disuse Atrophy, Spinopontine Atrophies, Atrophies, Spinopontine, Atrophy, Spinopontine