Just that really. Last night my DD woke up about 10.45 screaming blue murder and didn't settle back to sleep herself as she normally does if she stirs in the night. When I went in she was still lying down with her eyes closed but screaming and crying. I comforted her, but this woke her up properly and then it took 2 hours for her to go back to sleep! I gave her some calpol incase it was pain, but that didn't work so I think it was something else.
She has done exactly this once before, about 2 weeks ago (except we were up for 3 hours trying to settle her that time...)