My daughter is 14mo old, when we moved into our new house 3+mo ago, she started screaming in the middle of the night. The first time it happened it scared me to death. She was completely limp, wouldn't open her eyes and screamed as if she were in pain. Luckily my mother in law was visiting and she was a nurse at Bethany Home Birthing Center, she said that there was nothing wrong with her, but that she wasn't awake. We have learned that the only thing that helps is her daddy's cell phone, the lights and ringtones wake her up and calm her down. Once she's calm, we offer her a bottle then we put her back to bed. We've gotten used to the night terrors, they don't happen as often anymore, so if this is what your son is going through, maybe it will let up soon. I know most people don't like to dose their kids if they don't think they need it, but if this is an every night occurrance maybe you should try a dose of tylenol before bed and see if that helps. If he seems to sleep longer before waking up screaming or he doesn't wake up screaming at all, the culprit may be growing pains. If it is affecting his daytime routine severely I would make a dr appt just to make sure you aren't missing something else. Good luck!