Question: What is (are) Polymyositis ?
Answer: Polymyositis is a type of inflammatory myopathy, which refers to a group of muscle diseases characterized by chronic muscle inflammation and weakness. It involves skeletal muscles (those involved with making movement) on both sides of the body. Although it can affect people of all ages, most cases are seen in adults between the ages of 31 and 60. The exact cause of polymyositis is unknown; however, the disease shares many characteristics with autoimmune disorders which occur when the immune system mistakenly attacks healthy body tissues. It some cases, the condition may be associated with viral infections, malignancies, or connective tissue disorders. Although there is no cure for polymyositis, treatment can improve muscle strength and function.
Source: GARD