Myositis is a medical term that describes inflammation of muscle tissue, “myo” being a prefix denoting muscle, and “itis” being a suffix denoting inflammation of tissue. Putting them together gives “Myositis”, i.e. muscle inflammation.
In every-day life, inflammation is most commonly experienced as the swelling around the site of wounds and around muscle and joint injuries. But, with the conditions known collectively as Myositis, the inflammation is within the muscle tissue as a chronic autoimmune response.