Dyslexia, also known as reading disorder,
is characterized by trouble with reading despite normal intelligence. Different
people are affected to different degrees. Problems may include difficulties in
spelling words, reading quickly, writing words, "sounding out" words
in the head, pronouncing words when reading aloud and understanding what one
reads. Often these difficulties are first noticed at school. When someone who
previously could read loses their ability, it is known as "alexia".
The difficulties are involuntary and people with this disorder have a normal
desire to learn. People with dyslexia have higher rates of attention deficit
hyperactivity disorder (ADHD), developmental language disorders, and
difficulties with numbers.