Male 48 fall sleep around 10:30 pm wake up around 3 am go to bathroom and can't get to sleep again, it happens once in a while, stop drinking liquids at 7 pm, what could it be?

Enlarged prostate. Early awakening can be caused by: depression,waking to void secondary to enlarged prostate, sleep apnea...among other causes. If the awakening is only occasional that would likely eliminate depression as the cause(unless you are feeling depressed). The likely cause is enlargement of the prostate(BPH). Try to eliminate liquids after 7pm. For more on BPH see>http://bit.ly/1fJa24j Speak with your DR.