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
Review Date 4/27/2023
Updated by: Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.