Just asking what were you feeding him??
Sometimes I give my Hammy Bear too many treats (guilty momma here lol I can't help it sometimes bc she is just so cute and good) so when she eats too much she'll "scream" in her sleep too but when I see her shes fine! I think shes had a stomach ache bc after a couple days shes fine and sleeping normal but anyway your hammy sounds like they'll be fine!