What Are the 4 Main Types of Dyslexia?

The 4 types of dyslexia include phonological dyslexia, surface dyslexia, rapid naming deficit, and double deficit dyslexia.

Dyslexia is a learning disorder where the person often has difficulty reading and interpreting what they read. It is neither infectious nor brought on by vaccinations.

Dyslexia is not a form of autism.  While dyslexia is a learning difficulty, autism is a developmental disorder.

While a child may struggle with comprehension, spelling, and writing, dyslexia does not mean that the person is intellectually low. Rather, a person with dyslexia may have a better intelligence quotient than a regular person.

Dyslexia is a widespread disorder and is estimated to affect 5 to 10 percent of the population. Some claim that up to 17 percent of the population may have reading difficulties.

There are no official diagnostic types of dyslexia. Earlier dyslexia was classified into several different types, but new classifications of it include four types, which are proposed based on the symptoms.

1. Phonological dyslexia
   • This is also called dysphonetic or auditory dyslexia.
   • People with this type of dyslexia have difficulty processing the sounds of the individual letters and syllables and cannot match them with the written forms.
2. Surface dyslexia
   • This is also called dyseidetic or visual dyslexia.
   • This type of dyslexia is marked by difficulty recognizing whole words, which probably results from vision issues or visual processing difficulties in the brain.
   • With trouble recognizing the words, these people may have a hard time learning and memorizing words.
3. Rapid naming deficit
   • The person finds it difficult to name a letter, number, color, or object quickly and automatically. The processing speed is low and takes time to name them.
4. Double deficit dyslexia
   • The person with double deficit dyslexia shows deficits in both the phonological process and naming speed. The majority of the weakest readers fall under this category.

Dyslexia is caused by an overburden of impairments in reading abilities that the person cannot adjust to effectively.

It is often difficult to spot dyslexia in a child before they start attending school. People with dyslexia face challenges in reading, comprehending, and memorizing words.

Dyslexia is a condition that is present at birth and has a multifactorial etiology that includes:

• Inheritance of genes that are related to dyslexia, and this condition runs in the family
• Premature birth or low birth weight
• Exposure to harmful substances, such as nicotine, drugs, and alcohol during pregnancy may affect fetal brain development
• Brain development of the fetus may alter due to infections in the mother during pregnancy
• Differences in brain parts that are related to reading and comprehension
• Exposure to stress at a very young age
• Though dyslexia is present at birth, adults with brain injury, stroke, or dementia may develop the symptoms of dyslexia
• Dyslexia may worsen with age

However, this list is not comprehensive. In many cases, no specific cause may be found.

People with dyslexia face challenges in reading, comprehending, and memorizing words. However, early detection of the disorder and providing support to learn the words with other methods help them improve the condition.

The symptoms of dyslexia may be observed early in the preschool age and in school-going children and teenagers. Adults have distinctive symptoms that may lead to the diagnosis of dyslexia.

• Preschool children
  • Delayed speech development
  • Difficulty memorizing letters and colors
  • Choosing wrong words, reverse sounds, or confusion between words that sound similar
• Elementary and middle school children
  • Reading difficulty and may read more slowly than other children in the class
  • Difficulty processing information and memorizing things in a sequential order
  • Take longer to read and write
  • Trouble pronouncing new words or processing words with similar sounds
  • Avoid involving in tasks that include reading
• Teen and adults
  • Take time to process or summarize what they read or write
  • Struggle with spelling or learning a new language
  • Mispronounce words or difficulty memorizing text or doing math
  • Difficulty reading aloud
  • Difficulty conveying a story
  • Poor handwriting
  • Poor academic performance