How to differentiate hyperthyroid myopathy from the myopathies of hypothyroidism and idiopathic inflammatory myositis?
TSH | T4 | CK | Weakness | Biopsy | |
| Inflammatory myositis | Normal | Normal | Increased | Mild-severe | Inflammation |
| Hypothyroidism | Increased | Decreased | Increased | Usually mild | Normal |
| Hyperthyroidism | Decreased | Increased | Normal | Usually mild | Normal |
