A myopathy is a general term for a disease that affects the skeletal muscle (those which attach to bones). Skeletal muscles are the muscles that move the joints of the body.
Myopathies are often caused by inherited genetic defects. The most common being Duchenne and Becker muscular dystrophies.
Risk factors for other myopathies include the following:
- Autoimmune disorders (eg. thyroiditis)
- Exposure to toxins (eg. herbicides, insecticides, flame retardant chemicals)
- Endocrine disorders (eg. Cushing syndrome, hypothyroidism, hyperthyroidism, Addison disease)
- Infection (eg. HIV, Lyme disease, trichinosis)
- Vitamin D deficiency, vitamin E or A toxicity
- Medication (eg. some antihistamines, long-term corticosteroid use)
- Metabolic disorder (eg. glycogen and lipid storage diseases)
