Polymyositis & Dermatomyositis Support Group
Polymyositis (PM) is a type of chronic inflammation of the muscles (inflammatory myopathy) related to dermatomyositis and inclusion body myositis. The inflammation is predominantly of the endomysium in polymyositis, whereas dermatomyositis is characterized by primarily perimysial inflammation.
It is great that your tests came back normal. It sounds like the meds are working for you. I know you probably feel crummy with "normal" test results. Eventually, you will adjust and feel better over time.
Hang in there.