Hyperactivity is a state of too much muscle activity. This term is also used to describe a situation when a particular portion of the body is too active, such as when a gland produces too much of its particular hormone. See also attention deficit hyperactivity disorder (ADHD).

Hyperactive behavior usually refers to a group of characteristics. These can include constant activity, being easily distracted, impulsiveness, inability to concentrate, aggressiveness, and similar behaviors.

Typical behaviors may include fidgeting or constant moving, wandering, too much talking, and difficulty participating in quiet activities (such as reading).

Hyperactivity is not easily defined, because it often depends on the tolerance of the observer. Behavior that seems excessive to one observer may not seem excessive to another. However, certain children -- when compared to others -- are clearly far more active, which can become a problem if it interferes with school work or making friends.

Hyperactivity is often considered more of a problem for schools and parents than it is for the affected child. However, many hyperactive children are unhappy or even depressed. Hyperactive behavior may make a child a target for bullying, or make it harder to connect with other children. Schoolwork may be more difficult, and hyperactive kids are frequently punished for their behavior.

Hyperkinetic (excessive movement) behavior often decreases as the child grows older, and may disappear entirely by adolescence.

• Attention deficit disorder
• Emotional disorders
• Brain or central nervous system disorders
• Hyperthyroidism

A child who is normally very active often responds well to specific directions and a program of regular physical activity. A child with a hyperactivity disorder, on the other hand, has a hard time following directions and controlling impulses.