While inconvenient, the occasional need to urinate in the middle of the night also shouldn't be a major cause for concern. On the other hand, three or four late-night trips to the bathroom "is a bit more than what is considered normal," explains Dr. Ingber. Note that this does vary by age. While nocturia is pretty common in people over the age of 50, it's less usual for younger people to struggle from poor sleep due to waking up throughout the night to use the restroom.
It is worth doing what you can to remedy the situation: research shows that nocturia can be associated with long-term sleep deprivation, which itself is linked to its own risks for immunity, sense of well-being, and overall health status. If your sleep quality suffers due to an overactive bladder, and that three-hour rule isn't working for you, it's worth ceasing your liquid intake earlier in the evening and/or consulting your physician for further investigation.