A learning disability can best be defined as severe discrepancy between ability and achievement which cannot be attributed to another cause, such as physical handicap or lack of prior instruction. Learning disabilities are "hidden" disabilities, unlike other disabilities which present themselves to the outside world. Consequently, learning disabilites may be misunderstood and others may attribute learning disabilities to laziness, or intention to irritate others.
Approximately five percent of school aged children have a learning disability. The specific causes of learning disabilities are not known. Learning disabilities frequently manifest themselves in a specific academic area, such as reading, and students may excel at other subjects. Learning disabilites exist in all areas of academic, emotional, physical, and social development and are very heterogeneous group of disabilities.