I think my 8 month old boy is having nightmares? When i put him down to sleep he goes fine... a couple of hours later i will hear him scream so i go and check on him and hes still asleep and screaming... and when i pick him up he doesnt wake up for 20 mins and is still screaming!!

anyone know what it is???

try googling night terrors, I remember reading something about that a while ago when I thought my son was having nightmares, it sounds like that could be it?

Sounds like that's exactly what it is! My DS did the same thing around that age & sometimes still does, though it's a lot less frequent now. I found putting on a dim light would sometimes wake him up enough to calm him down. When DS got really bad I'd have to put him in front of a mirror to distract him. Unfortunately I don't think there's a lot you can do about it. Maybe try restricting TV a couple of hours before bed, if the family is watching it?? Or any active activity or loud activity. Eventually they grow out of it......or at least it becomes less frequent!! Horrible to go through though for us mummies......and the bubbies!! sad