Symptoms of ADHD in children and teenagers are broken into three distinct categories, inattention, hyperactivity, and impulsiveness. Inattention traits in children are marked by forgetfulness, inability to sit still, easily distracted and have a tendency to daydream. A child afflicted with hyperactivity traits will be unable to sit still, talks a lot and has to always be doing something. A child who is exhibiting impulsiveness traits will experience difficulty waiting.
The exact cause of ADHD is unknown, although there are several different factors that contribute to the condition, including heredity, chemical imbalances, brain changes, poor nutrition, exposure to toxins and brain injuries.