I wake up in the night having to urinate -- what's the problem?

Normal for aging men: Anyone will fill a bladder and have to wake up if they drink a lot of fluid before they go to bed. Most men have the prostate enlarge as a normal part of aging and that keeps the bladder from emptying all the way. A half full prostate has to empty more often as it fills more quickly and men have to wake 1-3 times a night at times. Saw palmeto may help over a few months.