Symptom Tests [Self-Test] Dyslexia in Adults. Could your lifelong reading and spelling challenges be the result of undiagnosed dyslexia? Take this quick self-test to find out if you show signs of a learning disability in addition to (or instead of) ADHD / ADD. Dyslexia is a learning disorder that involves difficulty reading due to problems identifying speech sounds and learning how they relate to letters and words (decoding). Also called reading disability, dyslexia affects areas of the brain that process language. 2 2. Slow Reading and Writing If required to do tasks that involve reading or writing, those with dyslexia may take an unusually long time to complete them.