Dyslexia is a learning difference characterized by difficulties with accurate word recognition and poor spelling and decoding abilities. It impedes the development of general knowledge and literacy skills. People with dyslexia have normal intelligence and usually have normal vision. Though there’s no cure for dyslexia, early assessment and intervention results in the best outcome. Sometimes dyslexia goes undiagnosed for years and isn’t recognized until adulthood, but it’s never too late to seek help.

Signs of dyslexia can be difficult to recognize before your child enters school, but some early clues may indicate a problem. Once your child reaches school age, your child’s teacher may be the first to notice a problem. Severity varies, but the condition often becomes apparent as a child starts learning to read.

Signs that a young child may be at risk of dyslexia include:

Late talking

Learning new words slowly

Problems forming words correctly, such as reversing sounds in words or confusing words that sound alike

Problems remembering or naming letters, numbers and colors

Difficulty learning nursery rhymes or playing rhyming games

Once your child is in school, dyslexia signs and symptoms may become more apparent, including:

Reading well below the expected level for age

Problems processing and understanding what he or she hears

Difficulty finding the right word or forming answers to questions

Problems remembering the sequence of things

Difficulty seeing or hearing similarities and differences in letters and words

Inability to sound out the pronunciation of an unfamiliar word

Difficulty spelling

Avoiding activities that involve reading

Dyslexia signs in teens and adults are similar to those in children. Some common dyslexia signs and symptoms in teens and adults include:

Difficulty reading, including reading aloud

Problems spelling

Avoiding activities that involve reading

Mispronouncing names or words, or problems retrieving words

Trouble understanding jokes or expressions that have a meaning not easily understood from the specific words.

Spending an unusually long-time completing tasks that involve reading or writing

Trouble learning a foreign language

Difficulty memorizing

Difficulty doing math problems

When dyslexia goes undiagnosed and untreated, childhood reading difficulties continue into adulthood.

Genes and heredity: Dyslexia often runs in families. About 40 percent of siblings of people with dyslexia also struggle with reading. As many as 49 percent of parents of kids with dyslexia have it, too. Scientists have also found genes linked to problems with reading and processing language.

Brain anatomy and activity: Brain imaging studies have shown brain differences between people with and without dyslexia. These differences happen in areas of the brain involved with key reading skills. Those skills are knowing how sounds are represented in words, and recognizing what written words look like.