(HealthDay News) -- Dyslexia is a learning disability that can significantly impair a person's ability to read and write.

The disorder varies from person to person, according to the U.S. National Institute of Neurological Disorders and Stroke (NINDS). But common characteristics usually include difficulty recognizing words and manipulating sounds, and the lack of ability to rapidly respond verbally to what a person sees.

How easily dyslexia is treated depends on the severity of a person's condition, the ability to tailor education programs to his needs, and whether the condition is diagnosed and treated early, the NINDS says.

A positive self-image and the support of family and friends also can make a significant difference, the agency says.