In medicine, 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 or elsewhere (e.g. , the brain etc.). Muscle cramps, stiffness, and spasm can also be associated with myopathy. Muscular disease can be classified as neuromuscular or musculoskeletal in nature. Some conditions, such as myositis, can be considered both neuromuscular and musculoskeletal.