How do i know if my son has hyperactivity or adhd?

My son is 5yrs old and since the age of 3yrs he has been so loud, so hyper and so it has made caring for him on some days unbearable. He is always talking, never stops even if its complete nonsense, he is very bossy and very rude and cant keep his legs and feet still even when sitting, he is always fidgeting and chattering even if its to himself. I thought he would become better behaved once at school and he isnt any better, even school call him a chatter box and he needs to sit still more. He manages to sleep for as little as 5hrs a night and still awakes hyperactive. He never sits still and is always on the go running around like an hooligan and its sooo draining! Ive asked the doctors and health visitor who all say he is an active little boy, but its not getting any better, is anyone used to this at all?