There’s no way to know how long your toothache will last. The duration of pain depends on the underlying cause. For instance, if you have temporary gum irritation, it should go away on its own in a day or two. But if you have a cavity or abscess, the pain may come and go somewhat, but it won’t go away completely. In many situations, a painful episode might go away as the nature of the inflammation is changing from acute to chronic. Thus, the level of pain will be diminished for a short period. Then, the pain and inflammation will eventually come back. This time an infection might even arise, which is very difficult to control. You might be quite ill, missing school or work, not been able to eat, drink and sleep. This will additionally weaken your immune system and you will be more prone to catch other diseases as the infection spreads.