The Diagnostic and Statistical Manual 5 (DSM-5) is the manual used widely by medical and allied health professions in Australia to describe and categorise problems that are diagnosed mainly by behaviour.
Its diagnosis of Specific Learning Disorder incorporates dyslexia and other severe learning difficulties, which are often called dysgraphia (problems learning writing/spelling) and dyscalculia (problems learning maths), though these latter terms aren’t used in DSM-5.
Dyslexia means severe and persistent reading difficulties which are generally based on problems with awareness of sounds in words, verbal memory and verbal processing speed.
Because so many people struggle with learning because of the way they have been taught, a diagnosis of Specific Learning Disorder is not given until the learner has had at least six months of evidence-based teaching (which in the case of dyslexia usually means explicit, systematic synthetic phonics teaching).
In both Australia and the UK there have been recent reports into the extent of dyslexia/literacy difficulties and what to do about them. You can find them here: