Doctors use heat, massage, and medicines in treating cramps. Hard muscular work also may cause skeletal muscles to become sore. In severe cases, the soreness may last up to four days. The cause of muscle soreness is not completely understood, but it probably involves damage to muscle and connective tissue. With proper exercise, the muscles and body can adapt to strenuous muscle work and greatly reduce the risk of tissue damage.
Numerous diseases affect skeletal muscles.
Two major classes of muscle diseases are muscular atrophy diseases and myopathies. Atrophy diseases attack and damage the nervous system, including nerves that stimulate muscles. As a result, muscles progressively shrink and become weak. Muscular weakness also occurs in myopathies. In these diseases, weakness results because the muscle itself does not function properly.