The American Psychiatric Association (APA) recognizes three major types of learning disorders. They are:

• Reading disorder. Also known as dyslexia, this condition prevents a person from correctly processing written words and other images from the eyes to the brain. Patients with dyslexia may have trouble reading and writing. In some cases, patients may have problems with speech. Dyslexia is one of the most common learning disorders, affecting an estimated 4 to 15 percent of the population. This disorder affects males and females equally, and it affects all ethnic and socio-economic groups in equal proportions.
  
  
• Mathematics disorder. Also known as dyscalculia, this condition involves difficulty performing math and manifests in many different forms. Patients with mathematics disorder may struggle with various concepts, such as linguistic skills (e.g., understanding and naming mathematical terms, operations and concepts), perceptual skills (e.g., grouping objects), attention-based skills (e.g., remembering to add “carried” numbers) and mathematical skills (e.g., following the right sequence of steps to arrive at a correct answer). Mathematics disorder is believed to affect about 1 percent of school-aged children, according to the APA. Because children do not begin substantial mathematics study until the end of first grade, it is typical for this disorder to go undiagnosed until second or third grade or later.
  
  
• Disorder of written expression. Also known as dysgraphia, this condition involves difficulty in both the physical act of writing and the intellectual task of composing text. Patients with this disorder have difficulty writing without grammatical and punctuation errors, poor paragraph structure and multiple spelling errors. Patients also often have extremely poor handwriting. In most cases, poor spelling and handwriting is not sufficient to warrant a diagnosis of this condition. This condition is less understood than other learning disorders and is not typically diagnosed until the second grade. Relatively little is known about the prognosis of those diagnosed with this disorder.

A fourth type of learning disorder called dyspraxia is recognized by many experts. Patients with this disorder have trouble planning and completing tasks that require the use of fine motor skills. It can impact everything from brushing one’s teeth to simply waving goodbye. About 2 percent of the general population has dyspraxia, and 70 percent of those with the condition are male, according to the National Center for Learning Disabilities.