Help!! 19mth old waking up crying at night?

My 19 mth old daughter is constantly crying and tossing and turning, seemingly distressed. she doesnt want to be comforted and still seems asleep. I think we have ruled out anything physical as urine and blood tests negative (besides from iron defieciency). Have researched 'night terrors' but it doesnt seem as 'terryfiying' as that. Any ideas??