Dyslexia, Causes, Signs and Symptoms, Diagnosis and Treatment.

Dyslexia, also known as reading disorder, is characterized by trouble with reading despite normal intelligence.[1][6] Different people are affected to different degrees.[3] Problems may include difficulties in spelling words, reading quickly, writing words, “sounding out“ words in the head, pronouncing words when reading aloud and understanding what one reads.[3][7] Often these difficulties are first noticed at school.[2] When someone who previously could read loses their ability, it is known as “alexia“.[3] The difficulties are involuntary and people with this disorder have a normal desire to learn.[3] People with dyslexia have higher rates of attention deficit hyperactivity disorder (ADHD), developmental language disorders, and difficulties with numbers.[2][8][9] Dyslexia is believed to be caused by the interaction of genetic and environmental factors.[2] Some cases run in families.[3] Dyslexia that develops due to a traumatic brain injury, stroke, or dementia is called “acquired dyslexia“.[1] The underlying mechanisms of dyslexia are problems within the brain’s language processing.[3] Dyslexia is diagnosed through a series of tests of memory, vision, spelling, and reading skills.[4] Dyslexia is separate from reading difficulties caused by hearing or vision problems or by insufficient teaching or opportunity to learn.[2] Treatment involves adjusting teaching methods to meet the person’s needs.[1] While not curing the underlying problem, it may decrease the degree or impact of symptoms.[10] Treatments targeting vision are not effective.[11] Dyslexia is the most common learning disability and occurs in all areas of the world.[12] It affects 3–7% of the population,[2][5] however, up to 20% of the general population may have some degree of symptoms.[13] While dyslexia is more often diagnosed in men,[2] it has been suggested that it affects men and women equally.[12] Some believe that dyslexia should be best considered as a different way of learning, with both benefits and downsides.[14][15]