Can growing to fast cause a child to act different?

My son is 6, he is very tall for his age, 4 feet 4 inches and weighs 70lbs. Most of the time he acts "normal" but there have been a few times in the past, and right now that for a few days to a week he acts soooo odd. Hyper at times, cant seem to control his body from moving, is very sensitive, crys for no reason(he usually never crys) Normaly he is a nervous boy, he needs to know where I am at all times, even when at home, If I have to go to the car to get something and I dont tell him he gets upset. He is always good in school, he sits well, follows direction and is a good student but, he is nervous in school when something new happens. I guess what I am asking is, if a child grows fast can that trigger something in thier bodies to make them "short circut". I am going to talk to the doctor about this but couldnt find anything online. For the past 3 days he has been acting so odd, doesn't look well, which also happens when he goes through these "phases".