<unk>  is disease featuring weakness and inflammation of muscles and (in some types) muscle pain. The cause of much<unk>  is unknown (idiopathic), and such cases are classified according to their symptoms and signs and electromyography, MRI and laboratory findings. It can also be associated with underlying cancer. The main classes of idiopathic<unk>  are polymyositis (PM), dermatomyositis (DM), and inclusion-body myositis (IBM).
Inflammatory myopathy
Metabolic myopathy
Acquired non-inflammatory myopathy
Nemaline myopathy
Polyradiculoneuropathy
Centronuclear myopathy
Polymyositis
Polyneuropathy