My almost 4 yr old son does strange spasms and noises when excited. grunting - hand flapping - tensing up and all of a sudden shouting/grunting. why?

Hard to say?: This could be normal behavior, would be helpful to see a video and understand the context of the rest of his developmental history. Does he have speech delay? Is he smiling? What is his face doing? Do you have other concerns about his development? Was his birth history uneventful? Is there a family history of delay, autism, or seizure disorder? See a pediatrician for advice!