Bodily functions or things that are out of order and devoid of proper operation. Physical defects are often confused in this world. The soul knows its own responsibility even if it cannot be expressed in this world. Sometimes there is some form of compensation such as a unique gift. They may even exist to provide atonement in others who have a particular service to perform.
Those who are insane, or not a responsible being, are often judged incorrectly with our worldly standards. We should allow for a difference between a soul's evolution and its limited expression in this world. It is a measure of soul responsibility and motive that is truly accounted for in the world of spirit.