Talk to Pediatrician on Sleep Disorder

My son is 3.5 years old and he used tk wake up from sleep screaming and yelling from a young age we thought that he must have gotten scared of something. Sometimes he would just hug his father and go to sleep other times he would scream and yell until I calmed him down or his father showed up. Recently since he has started to communicate better he gets scared in his sleep. When we wake him and him he makes weird expression and says there's some loud sound coming from somewhere and gets extremely scared. We try to calm him down but it goes away on his own and then he's completely normal and either goes to sleep or wakes up. Please tell me what I can do for this is this dangerous. I looked it up on Google and came across the term exploding head syndrome. What kind of doctor should we see for this?