Myopathy

Myopathy refers to diseases that affect muscle, including hereditary conditions such as muscular dystrophy, hormonal abnormalities such as hypothyroidism, and inflammatory conditions such as polymyositis.

Myopathy may be caused by a variety of hereditary conditions, metabolic abnormalities, hormonal abnormalities such as hypothyroidism, steroid use, and inflammatory conditions of the muscle such as polymyositis.

Symptoms and Diagnosis

Myopathy weakens the muscles, which can lead to difficulty walking, standing, holding things, opening jars, turning keys, chewing, swallowing, and talking. The disorder is diagnosed with a combination of blood tests and electromyography (EMG) -- tests that measure the ability of nerves and muscles to send and receive signals. Genetic tests also may be performed. In some cases, a biopsy of the muscle may be needed to confirm a diagnosis. A small sample of muscle from the thigh or upper arm is surgically removed under local anesthesia, usually on an outpatient basis. The sample may undergo various chemical and genetic tests to identify abnormalities.

Treatment

Treatment varies with the cause of the disease, but may include medication, vitamin supplements, avoidance of certain medications or substances, and physical or occupational therapy.