Conversion disorder is a disorder in which a person experiences blindness, paralysis, or other symptoms affecting the nervous system that cannot be explained solely by a physical illness or injury. Symptoms usually begin suddenly after a period of emotional or physical distress or psychological conflict. Conversion disorder is thought to be caused by the bodys reaction to a stressful physical or emotional event. Some research has identified potential neurological changes that may be related to symptoms of the disorder. Diagnosis of conversion disorder is based on identifying particular signs that are common among people with the disorder, as well as performing tests to rule out other causes of the symptoms. Treatment may include psychotherapy, hypnosis, and stress management training to help reduce symptoms. Treatment of any underlying psychological disorder is also recommended. The affected body part may require physical or occupational therapy until symptoms resolve.