Early diagnosis of dyslexia is crucial for developing normal reading comprehension levels in people with the learning disorder. About 74 percent of children who do not receive help for dyslexia before the third grade will remain poor readers in the ninth grade, according to the International Dyslexia Association. An initial visit to a physician is often spurred by speech or language difficulties or reading problems noted by parents and/or teachers. A physician will likely compile a thorough medical history and perform a complete physical examination to evaluate the child’s overall development.

Dyslexia cannot be diagnosed through a single test. Instead, a physician is likely to refer the patient to a specialist who will use a battery of tests that may help to accurately diagnose of the disorder. Many of these tests are designed to rule out other conditions that may be responsible for symptoms. Vision, hearing and neurological functioning will be tested to determine if another disorder may be the source of struggles with reading and writing. Specific speech, language and reading tests conducted by specialists may be recommended by the physician. Also, a mental health evaluation may be performed to look for social problems, anxiety or depression that may be causing or worsening problems.

In trying to diagnose dyslexia, a physician is likely to ask several questions to determine if certain markers are occurring, such as:

• Difficulty rhyming
• Difficulty naming letters or numbers
• Reading poorly
• Struggling to remember the right names for things
• Difficulty memorizing written lists and phone numbers
• Struggling to complete assignments and tests within a period of time

If dyslexia is suspected, educational tests may be performed to help evaluate the process the person uses to read and the quality those reading skills. In some cases, dyslexia is not diagnosed until adolescence or adulthood. Although a late diagnosis decreases the likelihood of a good prognosis, those affected can learn new ways of reading and writing at any age.

Dyslexia is diagnosed if the following conditions exist:

• Levels of reading (as measured by standardized testing) that are substantially lower than would be expected given the person’s age, level of intelligence and level of education.
  
  
• Level of reading that significantly interferes with school performance and day-to-day activities that require reading skills.
  
  
• If the patient has a sensory deficit (e.g., autism), the reading difficulty must be in excess of that typically experienced by others with the same deficit.