Signs and Symptoms of Myopathy
Although symptoms depend on the type of myopathy, some generalizations can be made. Skeletal muscle weakness is the hallmark of most myopathies, with some noticeable exceptions, such as myotonia and paramyotonia congenita. In these two inheritable muscular disorders, the muscles become enlarged, rather than weakened and atrophied, and do not relax after contracting.
In most myopathies, weakness occurs primarily in the muscles of the shoulders, upper arms, thighs, and pelvis (proximal muscles). In some cases, the distal muscles of the hands and feet may be involved during the advanced stage of disease.
Other typical symptoms of muscle disease include the following:
Initially, individuals may feel fatigued doing very light physical activity. Walking and climbing stairs may be difficult because of weakness in the pelvic and leg muscles that stabilize the trunk.
Patients often find it difficult to rise from a chair. As the myopathy progresses, there may be muscle wasting.