A child must have exhibited at least three of the following symptoms for at least six months to an extent that is unusual for their age and level of intelligence.
Runs around or excessively climbs over things
Unduly noisy in playing, or has difficulty in engaging in quiet leisure activities.
Leaves seat in classroom or in other situations where remaining seated is expected.
Fidgets with hands or feet or squirms on seat.
At least one of the following symptoms must have persisted at least for six months to an extent that is unusual for their age and level of intelligence.
Blurts out answers before the questions have been completed. Fails to wait in lines or await turns in games or group situations. Interrupts or intrudes on others, e.g. jump into others conversations or games.
Talks excessively without appropriate response to social restraint.
Pervasiveness of attention difficulties and hyperactivity
For a diagnosis or description of Attention deficit hyperactivity disorder (ADHD) a child would be expected to show the above difficulties in more than one setting, eg at school and at home.
Problems are not shown 'at home' but are very evident when a child goes to a hospital department. This can happen when parents do not realise that their child's behaviour is out of the normal range (perhaps because they have no other children, or they have other children who behave similarly). It may also be because the problems are mild, or because the family has handled the attention lack at home in such a way that it is not evident there is a major problem, or because the child is very young. In those cases it is quite reasonable for parents not to consider that their child has an attention deficit problem.