It can be difficult to
diagnosis because it may resemble many other diseases and varies from person to person.
Medical history and physical exam
Blood tests for autoantibodies and muscle enzymes. A muscle enzyme test called creatine
kinase, or CK, is most useful since the CK level tends to go up as the disease flares and
down when it diminishes.
Electromyogram (EMG) measures the electrical pattern of the muscles (like EKG of
heart).
