Who can diagnose
What kind of professional is qualified to diagnose dyslexia?
In most cases, testing for dyslexia is done by a licensed educational psychologist. Neurologists and other medical professionals may also be qualified to provide a formal diagnosis.
In the U.S., children who are having difficulties in school are legally entitled to request evaluation through their local school district. Parents can start the process by writing a letter to the school principal requesting evaluation for learning disabilities.
It is important to keep in mind that dyslexia is not a disease or an identifiable physical condition. Rather, it is a learning style that usually can be assessed through a profile that shows whether the child has a typical pattern of strengths and weaknesses, coupled with assessment to rule out other possible causes of symptoms, such as vision or hearing problems.
Formal assessment is usually necessary before a child can qualify for special services from his school, but it is not a prerequisite for getting help independently for specific academic problems such as reading difficulties.
Be aware that some individuals who claim to offer diagnostic testing services do not have the sort of educational credentials that would be seen as acceptable by schools or other agencies.
There are some fee-based services available online that may provide an informative report, but would not be accepted as providing an official diagnosis or documentation of dyslexia or any other learning disability.
Screenings geared to specific programs or treatments usually are not a substitute for formal diagnostic services. However, a formal diagnosis is not always needed; the main benefit of a formal diagnosis is that it can qualify a person to receive services or accommodations at their school or university, and may also be helpful to protect against workplace discrimination.
(Answer by Abigail Marshall)