Coming soon: AboutKidsHealth is getting a new look! Learn more Watch a video tour

Symptoms of ADHD

Worried boy in school

Children with ADHD may have symptoms of inattention, hyperactivity/impulsivity, or both.


A child with symptoms of inattention may:

  • make careless mistakes or fail to pay attention to detail
  • have difficulty paying attention to a task for more than a few minutes
  • not seem to listen when spoken to
  • not follow through on instructions or fail to finish schoolwork or chores
  • have trouble organizing tasks and activities
  • avoid or dislike tasks that require sustained mental effort, including homework or schoolwork
  • lose or have trouble keeping track of things that she needs, such as toys, books, or school assignments
  • be easily distracted
  • be forgetful

Hyperactivity and impulsivity

A child with symptoms of hyperactivity may:

  • often fidget or squirm in his seat
  • leave his seat when he is expected to remain seated
  • run around or climb when it is inappropriate
  • have trouble playing quietly
  • be often "on the go" or act as if "driven by a motor"
  • talk too much

A child with symptoms of impulsivity may:

  • blurt out answers before the question is finished
  • have trouble waiting for his turn
  • interrupt others

Hyperactivity and impulsivity are more noticeable than inattention. Symptoms of hyperactivity and impulsivity usually become less obvious as the child grows older. Teens and adults may not show outward signs of hyperactivity. They may feel a sense of inner restlessness instead.

ADHD symptoms are not always the same

Children with ADHD always have some symptoms. However:

  • They may look different in different children.
  • They may change depending on what the child is doing.
  • They may be different at school, at home, or in another setting.
  • They may change from day to day and from moment to moment.
  • They may become worse when the child is bored, unsupervised, or doing something difficult.
  • They may become better when the child is doing something he enjoys, when he is rewarded immediately, or when he is closely supervised.
  • They are often less noticeable in girls than in boys, because girls generally show just inattentive symptoms.

DSM-IV criteria for ADHD

The most widely used medical system for diagnosing ADHD is known as the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). It lists these criteria for ADHD:

  • evidence of at least six of nine symptoms of inattention and/or at least six of nine symptoms of hyperactivity/impulsivity, as listed above
  • symptoms are inappropriate for the child's age and stage of development
  • symptoms impair the child's functioning
  • symptoms appear in at least two areas of the child's life, such as at home, in the classroom, or in social settings
  • symptoms appear early in life, before age seven, and continue for at least six months

In Canada, the U.S.A., and many other countries, the child's pattern of behaviour is compared against these criteria to make a diagnosis of ADHD.

Symptoms of inattention and hyperactivity/impulsivity are discussed in more detail in this section. To learn more, please click the links on the left.

Peter Chaban, MA, MEd

Rosemary Tannock, PhD