my dog always tells me when he has to go outside when I'm awake but when I'm sleeping he won't hold it but he also won't wake me up. Is there anyway to encourage him to try to get my attention when I'm sleeping like he does when I'm awake?

Yes you can. there are many different ways too.

My dog automatically tells me if he has to go, even when I'm sleeping.Only thing was that I didn't train him to do it. He started doing it on his own.

Rather than letting the dog tell you when he has to go, it is much better for you to establish when he will go. I know that sounds weird and hard to do, but it's actually not.Basically, all you have to do is take the dog out at the same times, every day.... and make sure one of those times is right before bed. It will make things easier for you and the dog as well.

I never had that problem with my dogs once they were trained to ask to be let out, they made sure to wake me up in the night. Normally I took them out before I went to bed so they didn't bug me, You might just ask a veterinarian.