Fidgeting. Daydreaming. Extreme energy. Is it normal childhood behavior, or something more? Attention deficit hyperactivity disorder, or AD/HD, is the most frequently diagnosed childhood behavioral disorder and affects millions of Americans. A child who suffers from AD/HD is extremely hyperactive, has real trouble focusing and acts very impulsively. They can't take tests, can't sit still, and talk excessively, often interrupting others. Most children exhibit these behaviors sometimes. But for sufferers of AD/HD, these behaviors persist in a continuous fashion for more than 6 months, and affect the sufferer's ability to function-both at home and in the classroom. The first known reference to a child or one with attention deficit hyperactivity disorder occurs in the poems of the German physician Heinrich Hoffman, who in 1865 described 'fidgety Philip' as one who won't sit still, wriggles, giggles, swings backwards and forwards, tilts up his chair... growing rude and wild'. In 1902 by Sir George Still, a British doctor, published a series of lectures on impulsive children with significant behavioral problems, which ultimately led to the disorder being classified. Today, the exact cause of the disorder is still unknown, although scientists believe emphasize genetic factors. Causes that have been proposed, and dismissed, include poor parenting, bad diet and watching too much TV. The good news is that AD/HD symptoms can be treated with behavior management and medication. In a healthy brain, chemicals called neurotransmitters relay instructions for everything from body movements to memory recall. In AD/HD sufferers, some of these chemicals-namely dopamine aren't transmitted properly. To compensate, the brain looks for more stimulation. It does this by triggering body movement, or by alternating its focus. These actions do release more dopamine, but also cause the sufferer to be physically restless or mentally distracted. Most cases of AD/HD are diagnosed in children before age 7. Boys are three times as likely as girls to be diagnosed, but this difference levels off when boys reach the age of 19. By their 20's many formerly diagnosed children, especially boys, have outgrown the disorder, though symptoms often persist to adulthood for about 40% of sufferers. Professionals recognize three basic kinds of AD/HD. Children who have hyperactive-impulsive or HD will appear restless, fidgety and impatient and often consider immediate rewards rather than long-term consequences. Children who have inattentive AD/HD appear to be daydreamers. Because the primary symptom of this type AD/HD is an inability to focus on any one thing, it is also referred to as ADD or Attention Deficit Disorder. Patients who exhibit both hyperactivity and inattention are considered to have combined ADHD. AD/HD is not easy to diagnose. Symptoms may not be easily distinguishable from normal childhood behavior, and can also be caused by other disorders. If you believe you or a loved one may have AD/HD, talk with a physician about your concerns.