This is always a tricky question and many students come to an assessor asking for a dyslexia diagnosis when perhaps they would be better off going somewhere else first.
When you realise that you or a loved one is having a reading difficulty it is very easy to suppose that the cause is dyslexia. But perhaps not.
Other causes of reading difficulties may be;
Dyspraxia - this causes a number of difficulties with reading and eye tracking. Children have difficulty concentrating and are often fidgety. The child/adult may be working extra hard to form each letter when writing it. This will slow them down and mean they may forget their place in the word or even the sentence. As such their fine motor skills will be making spelling while writing very difficult. You may see an instant improvement when the child is allowed to dictate their spellings to a scribe or write their compositions on a word processing package.
Dyspraxic children may find organisation very difficult, including organising their body to sleep and will need a lot of support during the going to sleep process. This may include weighted blankets, blackout blinds and curtains, absolute silence or special music.
ADHD - this causes a lack of ability to avoid being distracted. The student with this will find everything around them instantly distracting. They will show high levels of activity and will not need much sleep. This is not a child who has difficulty going to sleep, but also needs to sleep late. This is a child who only needs a shorter sleep than others. The ADHD child will be finding concentrating in a normal classroom in the early years, nearly impossible and therefor may struggle to learn to read and write. They may find the ability to focus on a page long enough to study how the letters code for the phonemes very difficult and need a lot of support during these early stages.
ODD - this is oppositional defiant disorder. This child may just refuse to learn to read if they see no purpose for them to be able to do so. You will need to show them and prove to them why they need to be able to read to do the things they love. It may be wroth getting them into an video game which has a story line and adventure to it. You will have to get used to negotiating with this one and learn not to sweat the small stuff.
SALT - Speech and Language Difficulty. You may have noticed your dyspraxic or non-dyspraxic child has difficulty in pronouncing certain sounds or getting the sounds in the wrong order in a word. This is due to poor co-ordination in the facial muscles. This poor co-ordination in the facial muscles will be feeding through the speech and language processing areas of the brain and causing them to misinterpret the phonemes in the words they are trying to spell. They will also be mishearing them eventually. The early years brain learns to process the sounds they in hear in speech both form what they hear and how they pronounce them. Since they hear their pronunciation of a word/phoneme/syllable more often than they hear anyone else, their pronunciation has the biggest effect on what they learn. This, in turn will affect how they spell words and how they decode them as they read.
You need to spend a lot of time helping this child learn to make a wide a variety of noises; cars, buses, tractors, airplanes, various animals and monsters. Don't just make the typical brum, brum noises or say cluck, cluck. Actually listen to the noise and play a game of trying to imitate it properly so that others can't hear the difference.
Play up to his mispronunciations by responding to what he actually says and not to what you know he intends. Don't push it too far each time but just a little bit extra and then help him form the correct shapes in his mouth in correct order, slowly to help him say the word he actually wants. Think to yourself each time; 'Is this how I want him to talk when he gets to secondary school?'
This is such a big topic that I will pick it up again in another post.