According to the National Institutes of Health, the most prevalent health condition after the common cold is tooth decay.It’s more than likely that if you haven’t already had a cavity, you will develop at least one in your lifetime.So, how do you know if you have a cavity? Well, depending on the severity of your tooth decay, you may experience a variety of symptoms. Here are some of the accompanying symptoms that go along with tooth decay.• Nothing (in the early stages)• A toothache or spontaneous tooth pain• Tooth sensitivity• Pain (slight or severe) when eating something sweet, hot, or cold• Staining (brown, black, or white) on the surface of your tooth• Visible holes in your tooth. Those holes are cavities• Pain when biting downThe best time to catch a cavity is in the early stages, when there are few, if any, symptoms.