If your toilet is making a non-stop running sound it may be time to check the internal parts. You do not just want to ignore the sound and jiggle the handle, because it could be wasting gallons of water daily. Your toilet flapper could be decaying or have cracks; this flapper is what seals the water inside the tank. Your running toilet could also be due to the float height and it may need to be adjusted. Another cause could be that the fill valve seals are compromised and allowing water to continuously run and you will need the valves replaced.