Silent gerd can do it for many people. Most don`t know they have it but the acid, as strong as battery acid, trickles gently up the oesophagus. It can cause pain, which awakens, then you stand up for the loo and back down it goes, enough of an ache to waken but not enough to realise the cause
It can cause an irritating night time cough at times
I have had this for over 30 years, best to sleep on a slope but the bed wedge does not induce a comfortable night. Bricks to raise head of the bed, A slope made with pillows. Sleeping on the left side is better than sleeping on the right
I still get this even though I have my last light meal by 4pm. I always wake up, every single night but it helps that I know the cause and it is not usually a need for the loo. I go to my ensuite, drink some water, raise my pillow and quickly get back to sleep
I don`t take any medication and am an early bird, always in bed by 10 and awake with energy between 5 and 6, same all my life and my AC are all awake early too