Attention deficit hyperactivity disorder (ADHD) is a condition that can have obvious consequence on the lives of affected children, their parents and families. ADHD is not a illness like diabetes, nor is it a disorder with a single cause. 

Though the precise cause of ADHD remains a mystery, research has confirmed that ADHD has a very strong neurobiological basis. Although exact causes have not yet been identified, there is little question that heredity makes the largest influence on the incidents of the disorder in the population. In instances where there is no connection to family history, some other possible causes have been indentified. Complications during pregnancy, prenatal exposure to certain substances, premature delivery, significantly low birth weight, excessively levels of lead in the body and postnatal injury to the prefrontal regions of the brain, have all been found to contribute to the risk of ADHD. 

The tendency to develop ADHD involves complex genetic and environmental factors. ADHD symptoms generally appear before age seven although, for a variety of reasons, some children are not diagnosed until later.

ADHD may significantly affect a child’s life by impairing academic activities, peer relationships, and home life. 

ADHD makes it hard for people to control their attention, organize themselves and regulate their impulses. For some people with the hyperactivity component of ADHD, keeping quiet, staying seated or stopping all body movements is almost impossible. While everyone may have intermittent moments of daydreaming, fidgeting or forgetfulness, someone with ADHD experiences these difficulties often and in multiple settings; such as home and school; over a period of at least six months.

During the toddler and pre-school years, difficulties with paying attention, staying still and controlling impulses are expected from children. For example, children ages two to three are expected to be interested in their environment and to shift their attention from one toy to another. Similarly, young children are expected to move around a lot as they discover the world around them. As children progress through their childhood, however, most of them develop the capacity to control their behavior and concentrate on tasks as needed. Children with ADHD, in contrast, do not achieve age-appropriate levels of self-control, organization and concentration. 

Some children have inattention symptoms, others predominantly have hyperactivity and impulsivity symptoms, however, most children have a mixture of both types. 

All children with ADHD could struggle with low frustration, tolerance and have trouble following rules. They often show poor sportsmanship in games and they may seem intrusive or bossy in their play. As a result, children with ADHD face social challenges because their peers may find them as immature or annoying. 

Prompt identification of the underlying disorder and a comprehensive treatment plan can help avoid many difficulties. A trained clinician should integrate information from home, school and the clinical visit to make a diagnosis. 

There are various ways to measure ADHD. Psychologists use rating scales, questionnaires and other tests for collecting information from the child, their parents/caregivers and their teachers. Children would be observed at home and school.​​