How do you diagnose polymyositis?

EMG, MRI primarily: We suspect polymyositis (pm) when there is muscle weakness without pain occurs in the shoulder and hip areas (i.E difficulty brushing teeth, combing hair, getting up from chairs). Labs will show evidence of inflammation (high esr, crp) and muscle damage (high ck, aldolase). Electromyelogram (EMG) will show of muscle damage. Mri can show inflamed muscles. Muscle biopsy will definitely diagnose pm.

See details: Polymyositis is a diagnosis suggested by elevated muscle enzymes (cpk and aldolase) and confirmed by EMG and especially by muscle biopsy.