Did you know that girls and boys have very different signs, at times, of Attention Deficit Hyperactivity Disorder? The experts at WEB-MD want to help parents to make sure girls don't get left behind.

The symptoms of hyperactivity and impulsive behavior are perhaps the most visible. A-D-H-D affects an estimated eight to ten percent of school-age children. And most parents often begin to suspect A-D-H-D after repeated calls from their child's teacher saying he can't sit still or be quiet and his behavior is disrupting the class.

And boys are more likely to be diagnosed -- three boys to every girl. Girls, on the other hand are more likely to be inattentive than hyperactive or impulsive, so are often not diagnosed until much later.