Most people think of dyslexia as something a child has always had. A child struggles with reading, spelling or written work from an early age, and over time those difficulties become clearer.
But dyslexia-like difficulties can also appear later, even in a child or adult who previously read well.
This is known as acquired dyslexia.
Unlike developmental dyslexia, acquired dyslexia happens after a change in how the brain processes written language. It may follow an illness, brain injury, neurological event or health condition. For families, this can be confusing and frightening, especially when the person affected was previously doing well at school, college or work.
At BetterCare, we recently shared the case of a 14-year-old secondary school student* who experienced sudden literacy difficulties following a period of significant illness. Before becoming unwell, she had been a high-achieving student. Afterwards, reading became slow, effortful and far less automatic. She began decoding words syllable by syllable, and familiar words became harder to recognise quickly.
A psycho-educational assessment identified a highly uneven cognitive profile, with strengths in verbal reasoning and vocabulary, alongside difficulties with working memory, processing speed and visual processing.
What is acquired dyslexia?
Acquired dyslexia is a change in reading ability that develops after reading skills were already established.
This is different from developmental dyslexia, where difficulties are usually present from childhood and become more obvious as literacy demands increase.
With acquired dyslexia, the key difference is the change.
A child, teenager or adult may have been reading fluently before, but then begins to struggle with:
- Reading speed
- Recognising familiar words
- Following lines of text
- Understanding what they have read
- Spelling or writing
- Copying from the board
- Working under time pressure
- Remembering instructions
- Keeping up with school or work demands
The issue is not intelligence. In many cases, the person’s understanding, vocabulary and ideas remain strong. The difficulty lies in how information is being processed.
In the BetterCare case study, the student’s assessment showed that her verbal reasoning and conceptual understanding remained strong, but processing speed, working memory and visual processing were affected. This created a gap between what she was capable of understanding and what she could manage in everyday school tasks.
Why can reading suddenly become difficult?
Acquired dyslexia can happen when illness, injury or neurological change affects the systems involved in reading and language processing.
Reading may look simple from the outside, but it relies on many skills working together, including:
- Visual processing
- Memory
- Attention
- Language
- Processing speed
- Sequencing
- Eye-tracking
- Mental energy
- Executive functioning
When any of these are affected, reading can become much harder.
A person may still know the word, understand the topic and have the intelligence to complete the task, but the route to accessing written information becomes slower and more effortful.
This is why acquired dyslexia can be so frustrating. The person may feel like:
“I know I can do this, but my brain won’t let me do it the way it used to.”
Can Lyme disease cause dyslexia-like symptoms?
Lyme disease is one example of an illness that may affect the nervous system in some cases.
Lyme disease can cause or mimic dyslexia-like symptoms in children and adults, primarily through neurological impacts that may affect:
- Cognitive processing
- Reading and writing
- Memory
- Attention
- Processing speed
- Letter or number recognition
- Visual processing
- School or work performance
In children and teenagers, cognitive or neurological changes may show up first at school. Parents may notice homework taking much longer. Teachers may see a decline in written work, reading fluency, concentration, behaviour or attendance.
A child who previously coped well may suddenly seem:
- Overwhelmed
- Avoidant
- Frustrated
- Forgetful
- More tired than usual
- Less confident
- Inconsistent in their schoolwork
Lyme disease should not be assumed to be the cause of new reading difficulties. However, where there has been a significant illness and a sudden change in learning, it is important to take the change seriously and seek appropriate medical and educational assessment.
Signs parents and teachers may notice
Acquired dyslexia can be missed because the child may not “look” like someone with a learning difficulty. They may have years of strong school performance behind them. They may also be very good at masking their difficulties.
Signs can include:
- A sudden drop in reading fluency
- Reading becoming slow or tiring
- Losing place on the page
- Difficulty recognising familiar words
- Increased spelling mistakes
- Trouble copying from the board
- Taking much longer to complete homework
- Avoiding reading or written tasks
- Increased frustration, anxiety or low confidence
- Gaps in school attendance after illness
- A mismatch between verbal ability and written work
- Struggling more under timed conditions
- Declining academic performance
- Behavioural changes
- Difficulty keeping up with lessons or assignments
For schools, the biggest clue is often a clear change from the student’s previous level of performance.
A child who was once confident may begin handing in incomplete work. A teenager who once read easily may stop volunteering in class. A previously organised student may start forgetting instructions or missing deadlines.
These changes are not laziness. They may reflect a real shift in processing, stamina or cognitive load.
Why assessment matters
A comprehensive psycho-educational assessment helps identify what is happening beneath the surface.
It can look at areas such as:
- Reading accuracy and fluency
- Spelling and writing
- Working memory
- Processing speed
- Visual processing
- Verbal reasoning
- Attention and concentration
- Learning profile
- Strengths as well as challenges
This matters because two students can have the same outward problem, such as slow reading, but for very different reasons.
For example:
- One student may be struggling with phonological processing.
- Another may have visual processing difficulties.
- Another may be affected by working memory.
- Another may be struggling because of fatigue, attention or processing speed.
The right supports depend on understanding the profile.
In the our acquired dylexia case study, the assessment helped identify acquired dyslexia secondary to the neurological impact of chronic illness.
The recommendations included:
- Extra time in exams
- Assistive technology
- Reduced workload
- Alternative formats for learning
- Structured literacy support
- Breaking tasks into smaller steps
- Reducing copying and note-taking demands
- Support with working memory and processing speed
- Practical recommendations for home and school
Support can make a real difference
The right supports can help a student continue learning while reducing unnecessary pressure.
Helpful school supports may include:
- Extra time in exams
- Reader support or assistive technology where appropriate
- Text-to-speech tools
- Audiobooks or alternative formats
- Reduced copying from the board
- Printed notes or slides
- Shorter written tasks where possible
- Clear written and verbal instructions
- Breaking assignments into smaller steps
- Flexibility around attendance and workload
- Structured literacy support
- Regular communication between home and school
Wellbeing support is also important. A sudden change in learning can affect confidence, identity and mood, especially for a student who previously saw themselves as capable and independent.
The message should not be:
“You can’t do this anymore.”
It should be:
“Your brain is working differently right now. Let’s understand what has changed and put the right supports around you.”
When to seek help
Parents should consider seeking advice if a child or teenager shows a sudden or significant change in reading, writing, concentration or school performance, especially after illness, injury or a period of neurological symptoms.
It can be helpful to speak with:
- The child’s GP or medical team
- School staff
- The school’s learning support team
- An educational psychologist
- A psychologist or therapist if confidence, anxiety or adjustment are affected
Early recognition matters. The sooner the difficulty is understood, the sooner support can be put in place.
Acquired dyslexia is not a loss of intelligence
One of the most important points is this: acquired dyslexia does not mean a child or adult has lost their ability, intelligence or potential.
It means that something has changed in how they access written information.
With timely assessment, practical supports and a compassionate approach, students can continue to learn, rebuild confidence and access their strengths.
At BetterCare, our psycho-educational assessments help children, teenagers and adults better understand their learning profile and the supports that may help at home, in school, in college or at work.
If you are concerned about a sudden change in reading, writing or school performance, a psycho-educational assessment can be an important first step.
BetterCare offers private psycho-educational assessments for children, teenagers and adults in Ireland. You can send us a message here, or Phone: (01) 556 3335. Whenever you’re ready, we’re here to help.
*To protect the patient’s privacy, their name and some identifying details have been changed.
