Learning disabilities (LD) vary from person to person. One person with learning disabilities may not have the same kind of learning problems as another person with learning disabilities. One person may have trouble with reading and writing. Another person with learning disabilities may have problems with understanding math. Still another person may have trouble in each of these areas, as well as with understanding what people are saying.Researchers think that learning disabilities are caused by differences in how a person's brain works and how it processes information. Children with learning disabilities are not "dumb" or "lazy." In fact, they usually have average or above average intelligence. Their brains just process information differently.