Sleep disturbances

I'm just wondering, what time does he go to bed? How is it affecting him during the day? Is there anything else going on, like teething etc, which could be upsetting him? This could easily be throwing out his usual sleeping patterns.

My first suggestion was to provide him some reassurance in the cot but not to get him out when he wakes. By reassurance, I mean go in and try to settle him for sleep again and keep trying until around 6.30 am which is a 'reasonable' time to be up IYKWIM? I know this might seem like a long time to be re-settling if you're up at 4.30am, but the problem is that if he starts waking even earlier than 4.30 am and your immediate response is to get him up, he will most likely wake and do the same thing....even if it's at 2 am which is definitely not when you want to be up!

I'm not sure what your settling techniques are or have been in the past, but perhaps you may need to revisit them or try another strategy in this regard. Jacob's sleeping patterns became quite disturbed at around 6.5m due to teething and at 9.5m we were in a Mother & Baby Unit and they strongly recommend that you provide comfort when baby is crying (they don't encourage controlled crying which I found a positive thing) so that the baby knows you are there when they need you, but to also try and help them back to sleep and encourage them to 're-learn' those self-settling techniques.

If it's bad dreams, or perhaps that he is afraid of the dark, have you tried a little night light that might reassure him? Perhaps leave a light on outside his room that will provide some light as an alternative?

HTH!!!