Recently my son was diagnosed with both ADHD and ADD. I'm confused: How can he have a combined type? My son has many learning disabilities and is physically small in both height and weight for his age -- 35 pounds when he entered the first grade. I was told after a bone age test that he was the size of a three-and-a-half-year-old. Do you think that this may have something to do with the diagnosis? He's not on any medication because of the above.
There are three types of ADHD
(Attention Deficit/Hyperactivity Disorder): predominantly inattentive type; predominantly hyperactive-impulsive type; and combined type. Some children with ADHD show symptoms of inattention and aren't hyperactive or impulsive. Others might only show symptoms of hyperactivity-impulsivity. Most, however, show symptoms of both inattention and hyperactivity. The term ADHD is technically correct for any of these types, but in the past, the term attention deficit disorder (ADD) was used and is still used by many. For the last ten years or so, the terms ADD and ADHD have been used interchangeably. I would go back to your doctor or whoever made the diagnosis and find out exactly what he meant.
As to the other part of your question, I can't say that your child's small stature has anything to do with the diagnosis of ADHD. If he suffered some trauma at birth, that could certainly have long-range effects on learning and behavior. This is something to discuss with your pediatrician if you are concerned.