The need to get up and urinate breaks my sleep into two parts on many nights, and sometimes it's hard to get back to sleep afterwards, leading to very little sleep for those days. I've tried not drinking liquids after noon, and it would still plague me pretty often. I guess it could be that I sleep too lightly between REM phases, maybe, so that minor disturbances wake me up?
For such cases, I've taken to starting the BBC World Service stream on my phone's speaker at low volume. Just loud enough to be a presence but at or below the threshold where I can easily make out the words.
Without really paying attention to the news/program, it seems to "short circuit" my attention or whatever's going on in my mind, enough that I usually drift off within a few minutes.
Anecdote, but with a success of 1 (person).
P.S. I used to find the idea of sleeping with the TV or radio on counterproductive, and I still wouldn't do it at normal volume, but this hack has worked to let me doze off when that's not happening on its own. My normal and long-standing bedtime routine is usually to read for a few minutes until tiredness overtakes me.
P.P.S. I should mention that I also have white noise playing in the bedroom, due to intermittent neighborhood noise issues. Perhaps the BBC stream would be too distracting without the white noise's presence.
I read Terry Pratchett at bedtime on my phone at the lowest brightness possible. It's interesting enough that I want to read it, but rarely edgy enough to spike my adrenaline.
I usually know if I am not going to get back to sleep.
In which case I take one anti-histamine and that just shifts me enough over the edge to push me back to sleep. It is a choice between two bad things: (1) not sleeping, or (2) taking a pill I don’t want to; however sleep matters more to me. I intend to find something else that “causes drowsiness” that isn’t so systemic, but I think having a solution that works is fantastic. I certainly want to avoid hypnotics - I would worry about the long term side-effects.
If you haven't seen a sleep specialist, I'd start there. I had pretty bad sleep issues that I finally got checked out, and after getting a CPAP I have been sleeping better than I had in a decade.
I had a home sleep study. I've had a CPAP for close to a year now. It's helped with my breathing but I still wake up after 4.5 hours of sleep everyday.
Another factor may be lifestyle choices. Not saying you are affected by these, but being older, drinking alcohol at night, or ingesting caffeine(even tea) past, say, 2 PM, certain medications, not following a set time to sleep, or getting woken by the sun are all potential factors, so you should continue to consult with your health care professionals.