Myositis is an inflammatory condition that affects the muscles, leading to weakness and discomfort. It can occur due to various causes, including autoimmune diseases, infections, or certain medications. The inflammation can damage muscle fibers, making it difficult for individuals to perform everyday activities. There are different types of myositis, such as polymyositis and dermatomyositis, each with unique symptoms and characteristics. Diagnosis typically involves blood tests, imaging studies, and sometimes muscle biopsies. Treatment often includes medications to reduce inflammation and physical therapy to improve muscle strength and function.