Could my son has ADHD at age of 3

[Kim]

Hey everyone i was just wondering if my son could have ADHD he was 3 in august, my brother was diagnosed with ADHD properly about a year ago at 17.
My sons always on the go he's always jumping off things and into things he has no fear he will jump off the top of a climbing frame and the kitchen sides, he's always bumping into things his front two teeth have died from him hitting them on things and he chipped one the other day,
He went to his 2 and half year check and they said his concentration was poor and they would look into it further at his 3 year check, he dosent focus on one thing for a long time he would rather play with or do something for 5 minutes then something else would interest him.
Hes's always shouting and its like he dosent hear what im telling him, his preschool suggest i take him to get a hearing test because he is always shouting instead of speaking quietly.
Hes a bit of a handfull at the best of times
He gets frustrated really easily if i tell him off he gets very frustrated to the point he starts shaking and trying to bite me!
Theres a few other things but i was just wondering if it was a possibility at all? and at what age are children usually diagnosed??
thanks 

[Sara]

My 9 year old has Attention Deficit Hyperactive Disorder. For years we have felt hopeless, worried, confused and alone. I have taken my son to 9 different doctors. The majority of them knew very little about it and very few had ever had an ADHD patient. So many times we took him to doctors so they could study him and learn. That made us feel alone and frustrated. Our poor son was having to battle this alone with our best efforts at helping.

Finally I came upon our current doctor. He takes the time to find the right medication, he contacts the school every 2 months to see how he is doing and he was able to get him top of the list for counseling through the government. I can finally take a deep breath now that the weight is not all on me.

[Alice]

Normally they will not be diagnosed until school age.

[John]

Doctors have no idea how to help. They use only medications to slowdown activity.

[Bob]

Maybe you can try Neutralizers

Nobody could help me, they did