I am also going to say it is probably the teething. My daughter (who has slept through the night since she was 3 months old) started doing the same thing a month ago, she is now 10 months old and she still does it. The first time she started waking up at night screaming I didn't know what it was, but within a week or so I noticed her 2 first teeth coming through. It's been going on for a month now and I thought it would be over by now, but now this week she has 4 of her top teeth that just broke through within a couple days of each other! So, I'm hoping there's a break after this from teeth for a little bit, for her sake. I can't imagine how it feels to have teeth breaking through your gums! I did take her to the doctors a couple weeks ago because I wanted to make sure it wasn't an ear infection since she had been pulling at her ears and he said it was just teething. It just hurts them more at night because they're calming down and not pre-occupied, so they realize that it hurts and that is why it is worse at night. So, I would just keep up the oragel and some tylenol before bedtime and hopefully it will get better!! I also give my daughter frozen peaches in those little mesh strainer bags after dinner, just to help keep her gums cold. Good luck!!