My lips go numb almost daily for hours at a time what could be causing this?

Need evaluation. This could be nuerologic and would recommend a neurologic evaluation and possibly a brain mri. Vascular causes are less lilely. Do they change color? Does naything cause this to occur? How long do they stay numb? Is it both upper and lower lips and right and left sides. We would need more clarification which you will get with your evaluation.