Why do I always feel like I need to pee although my bladder is empty?

Urgency. The frequent desire to urinate despite low bladder volumes can come from problems within the bladder, like inflammation and infection, things outside of the bladder like spinal injury, excessive nicotine or caffeine use, or it can be idiopathic, without a clearly identifiable cause. A simple history, physical examination and urinalysis can start your physician down the path towards figuring it out.