G71: Primary disorders of muscles

G71.1: Myotonic disorders

Your disorder may be hereditary. If so, other members of your family may be affected. The disorder is also sometimes caused by medications, for example.

The disorder may cause a variety of symptoms. The muscles may not be relaxing properly. In that case the muscles will feel stiff. Some muscles may also get weaker or become sore. Normal movement may become impossible.

The disorder may also affect other organs. Then, the person may sometimes become very tired, or be unable to see properly. In some cases, the disorder also affects the respiratory muscles and the heart muscles. Then breathing often becomes more difficult and the person may be seriously ill.