Hyperactivity describes a state of heightened activity, movement, energy, and behaviors. Increased speech, impulsiveness, and a short attention span can also be a result of hyperactivity. A person who is hyperactive may also be fidgety and have difficulty concentrating. The word 'hyper' is often used to describe this state. Although experienced by most people at some point and a common trait in some individuals chronic or excessive hyperactivity can be a symptom of attention-deficit hyperactivity disorder (ADHD).
An example of a hyperactive child would be one who is running around the room, talking excessively, and not being able to focus on any particular task.