Myositis is an inflammation or swelling of the muscles. It is most often caused by injury, infection, medicines, or an autoimmune disorder.
Amato AA. Disorders of the skeletal muscle. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice. 7th ed. Philadelphia, PA: Elsevier; 2016:chap 110.
Greenberg SA. Inflammatory myopathies. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 269.
Taber's Medical Dictionary Online. Myositis. www.tabers.com/tabersonline/view/Tabers-Dictionary/729759/all/myositis. Accessed June 10, 2019.
Review Date 5/13/2019
Updated by: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.