The good news is that you can't see your taste buds, so what you are referring to are the papilla on your tongue, of which there are thousands. It is not uncommon for one of them, or a small group of them to become irritated, from everything from rubbing your tonge against the backside of your lower teeth (subconciously) to irritating them during eating. Your tongue should be brushed regularly like your teeth, and if something is building up on it, this should remove it. The questions become, does it actually develop into a sore that you can see, or does it develop a white coating that is visible and returns after brushing.? The sore, like a small ulcer is something you really have to have checked out. A white coating could be something as simple as Candida, which while it needs some treatment, isn't a big deal or anything to worry about.