Hello and welcome to HCM,

Thank you for your query.

First coming to the classification. As ADHD has 3 different types:

1. Combined ADHD (which includes all symptoms -I shall mention them below)
2. Inattentive ADHD (poor concentration and attention)
3. Hyperactive-impulsive ADHD (hyperactivity is present, but poor attention is almost never seen)

Symptoms are as follows:
1. Of inattention-
-Short attention span (shifting from one activity to another very fast and usually without completing the first one)
-Poor attention leading to careless and messy mistakes (usually only observed once the child starts attending school)
-Easily distracted by a stimuli not intended to distract the child (unintentional stimuli causing distraction)
-Disorganized (seen in the arrangement of room, clothes, books, etc)
-Gives priority to less important things and puts more important ones aside
-Cannot finish simple tasks given at school (homework, etc.)
-Forgetfulness
-Jumping from one topic to another while speaking

2. Of hyperactivity-

-Fidgeting while asked to be seated (common even in normal children, but please note that it will be present along with other presentation)
-Hyperactivity: frequently moving or running around
-Not tiring easily
-Restlessness
-Talking excessively

3. Impulsiveness-

-Impatience
-Answering before question is completely
-Delayed response
-Finds it impossible to wait ones turn
-Initiating tasks or conversations in inappropriate times

I would also advise you to give him some more time, as he is 5 years old, and many children are hyperactive at this stage. If you find a strong similarity with the above given symptoms, you could consult your Family Physician or a child Psychiatrist for a better and more in depth analysis.

You can always write back to us for more information. I would be happy to answer your queries.

Warm regards.