What Is Dyslexia?

Why does dyslexia start with spoken language?

Dyslexia starts with spoken language because written English is a code for speech sounds. To read the word "chat", a child has to know that the spoken word is made of three sounds, ch, a and t, and that each one is written with particular letters. Hearing a word as separate sounds is the step a child with dyslexia finds hard, so the letters have nothing firm to attach to.

This difficulty is there before school. A review in the Oxford Review of Education reports that the difficulty with speech sounds in dyslexia can be found in the preschool years, long before reading is taught. It travels with other spoken language difficulties: learning new words, holding words in memory for a few seconds and finding the right word quickly. SPELD NSW puts it in one line: people with dyslexia have difficulty working with the sounds in language and with the written form of language. The guide to dyslexia and spoken language explains each of these skills and what a parent hears at home.

It is also the reason a speech pathologist works with dyslexia. The sounds of speech, and how children learn them, are a speech pathologist's field.

What does dyslexia do to reading and spelling?

Dyslexia makes single words hard to read and hard to spell. A child who cannot easily match letters to sounds has to work out each word slowly or guess at it, and words they have never seen before are the hardest of all. Spelling runs the same code in the other direction, from sounds to letters, so it is affected as well.

Understanding suffers second hand. The Australian Dyslexia Association notes that dyslexia is not at its root a problem with comprehension: the central difficulty is turning letters into sounds and sounds into letters. When every word takes effort, though, there is little attention left for what the sentence meant.

What is it like to have dyslexia?

For a child, having dyslexia means doing by slow effort what classmates do without thinking. Each word has to be worked out, and reading aloud shows that effort to the whole class. healthdirect lists what often follows in the primary school years: guessing at words, avoiding reading, especially out loud, anxiety about school and signs of low self-esteem. Many children with dyslexia also find it hard to hold information in mind while they work with it, which shows up when an instruction has several steps.

A child with dyslexia usually knows they are working harder than the child beside them. Without an explanation, it is easy for them to decide they are not clever. Giving them the real reason is part of the help, and the guide to talking to your child about dyslexia covers how.

Parents usually notice a child who talks well but is slow to learn letter sounds, guesses at words and tires quickly when reading. Later the reading may become accurate but stay slow, and spelling stays hard. Whether one child's reading difficulty is dyslexia is a question an assessment answers, and what the first assessment looks at is set out on the how it works page.

What is different in the brain with dyslexia?

Dyslexia is a difference in how the brain handles written language. A review of dyslexia research in The Lancet reports that brain imaging studies most often find less activity during reading in two areas at the back of the left side of the brain. One is involved in processing speech sounds and matching them to letters, the other in recognising written words. The same review describes dyslexia as running in families and moderately heritable. What that means for brothers and sisters is in the guide to what causes dyslexia.

Dyslexia affects somewhere between 1 in 20 and 1 in 5 people, depending on who is counted. The figure most Australian sources use is about 1 in 10.

Source	Figure	Who is counted
The Lancet review (2012)	About 7%	Children whose reading is well below the average for their age, on a strict cut-off
SPELD NSW	5 to 10%	People with dyslexia
healthdirect	About 1 in 10	People with dyslexia
Australian Dyslexia Association	About 10%, and up to 1 in 5	The higher figure includes mild dyslexia as well as severe

The sources differ because dyslexia has no sharp edge. Reading ability runs along a range, and researchers describe dyslexia as the low end of that range with no clear cut-off, in the way there is no single point where blood pressure becomes high. Draw the line strictly and about 7% of children fall below it. Include milder difficulty and the figure rises towards 1 in 5. Mild, severe and the other labels are sorted out in the guide to types of dyslexia.

Boys are identified more often than girls. The Lancet review puts the true difference at between 1.5 and 3 boys for every girl. The gap among children referred for help is wider, because boys with dyslexia come to attention more often.

What is the formal name for dyslexia?

The formal name is specific learning disorder with impairment in reading. It is the term a psychologist's report uses, and a formal diagnosis of dyslexia is usually made by a psychologist. Dr Lauren Crumlish, a Certified Practising Speech Pathologist, does not diagnose dyslexia: she assesses reading, spelling and the language skills underneath, and teaches from what the assessment shows. What the formal status means in law, at school and for funding is in the guide on whether dyslexia is a disability .

What to do next

If this page describes your child, the next question is what helps. The short answer is explicit, structured teaching of how sounds and letters work, and the page on dyslexia treatment sets out what works and what does not. If your child has just been identified, the dyslexia support page covers the first month, at home and with the school.

The steps are on how online dyslexia therapy works.