Hyperactivity means the state or condition of being excessively or pathologically active. All the subcategories of hyperactivity have to do with the inability to keep still and the actions a person with ADD might do because of their restless traits. Impulsivity means actuated by or prone to act on impulse. The subcategories of impulsivity are actions that are a result to acting on impulse.
There are three distinct forms of Attention Deficit Disorder. Outwardly Expressive ADD, Inwardly Directed ADD, and Highly Structured ADD. These three are not set types for every person; a person can have a combination of these three types. Outwardly Expressive ADD is a type of ADD where a person communicates so that everyone knows what he or she is feeling. This behaviour is characterized by hyperactivity, impulsive behaviour, a low frustration threshold, high level risk taking, difficulty with long term projects, and little interest in details, lack of temper control, expressive moods, and having an outgoing personality. I, myself is diagnosed with Outwardly Expressive ADD. I didn't realize I had this until moving here and noticing my short temper, and inability to finish