Meaning of polymyositis: An inflammatory disease of the muscles closest to the center of the body.

Definition of polymyositis

An inflammatory disease of the muscles closest to the center of the body. It causes weakness, inability to stand, climb stairs, lift, or reach. It may also cause muscle pain and difficulty swallowing, and may affect the lungs and heart. Having polymyositis increases the risk of certain types of cancer.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.