I've always been a light sleeper...well, ever since my first child was born 25 years ago! Ever since then I've slept with one eye open. I've always been an early bird, though.
I started having the sleep interruptions every two hours. I'd sleep for two hours, wake up and it would take me 30 minutes to an hour to go back to sleep.
I think as we get older our bodies are adjusting to the change and sleep is one of the things affected. Just my take on it - nothing scientific to prove it.
I've tried not to get too wrapped up in it because I know I can take a nap if needed (tho I'd rather sleep at night and not during the day). Seems the more I stress about it the worse I sleep. I've tried Advil PM and Somenex and they both made me sleepy but neither
kept me asleep. I had a prescription for Ambien but my Neuro told me not to take it every night as it messes up the sleep hormones.

I think my sleep hormones are already messed up...hence the need for a sleep aid!!

On a side note...I've just upped my LDN dose to 3.0 and I slept better last night than I have in a long time. It may not last but I'll take it while I can get it!!
Good luck - and let us know if you find something that works for you!