Need help diagnose possible mental health problem?

we have never gone to the doctor about it although my mum says every time she should about my brother. My brother wil shout and shout and shout and never listen and they talk over you and its not just a teenage problem. when he gets shouted at he wil put his hands over his head and shake his head and huddle in a corner and then lash out and try to "protect himself" and when someone trys to puss him towards the door he will throw himself in a heap and cry. and he is very persistant he will never give up on something like when he is getting shouted at he will keep trying to get past into the other room to try like empty the dishwasher (or whatevver hes got the row for)..we have had the thought of it being asburgers or however you spell it but im not sure and i know i havent exactly gave any proper like symptoms but theres something wrong with him. and im tired off it i keep faling out with him and my parents beacause of it and sit in my room crying.