Definition

Myositis is an inflammation or swelling of the muscles. It is most often caused by injury, infection, medicines, or an autoimmune disorder.

Dermatomyositis and polymyositis are related topics.

Alternative Names

Inflammatory myopathies

References

Doughty CT, Amato AA. Disorders of the skeletal muscle. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Inc; 2022:chap 109.

Selcen D. Muscle diseases. In: Goldman L, Cooney KA, eds. Goldman- Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 389.

Taber's Cyclopedic Medical Dictionary. 24th ed. Philadelphia, PA: F.A. Davis Company; 2021. Myositis. www.tabers.com/tabersonline/view/Tabers-Dictionary/729759/all/myositis. Accessed March 31, 2025.