A myopathy is a muscular disease in which the muscle fibers do not function for any one of many reasons, resulting in muscular weakness. "Myopathy" simply means muscle disease. This meaning implies that the primary defect is within the muscle, as opposed to the nerves ("neuropathies" or "neurogenic" disorders) or elsewhere.
Non-inflammatory myopathy of endocrine origin is a muscle disease which results due to endocrine maladies such as hypo- or hyperthyroidism. This condition is also associated with corticosteroid use.
In this condition, endocrine gland malfunctions and produces too much or too little hormones. One of the many functions of these hormones is to help regulate muscle activities. Problems in hormone production lead to muscle weakness.
Hyperthyroid myopathy and hypothyroid myopathy affect different muscles in different ways. Hyperthyroid myopathy occurs when the thyroid gland produces too much of the hormone thyroxine, leading to muscle weakness, some muscle wasting in hips and shoulders, and, sometimes, problems with eye muscles. The hypothyroid type of myopathy occurs when too little hormone is produced, leading to stiffness, cramps, and weakness of arm and leg muscles.
Common symptoms associated with this disorder are:
Loss of muscle bulk
Difficulty in swallowing (dysphagia)