A cavity is a decayed part of the tooth, and it can make itself known in a variety of ways depending on how serious it is and where it is in the mouth. Usually symptoms are not noticeable until the area of the decay gets larger.
Here are a few signs that indicate the early stages of tooth decay:
1) Tooth sensitivity
When one experiences tooth sensitivity, the pain can be mild or more severe and usually strikes when you eat foods or drink beverages that are exceptionally hot or cold. Even highly sweet foods and liquids can cause this painful sensation.
Dark stains on teeth that appear brownish or black could be another indication of a cavity.They can be tiny enough so as to resemble tiny dark dots.
Holes and gaps between teeth can lead to food getting deposited that lead to cavities. As a cavity progresses you might start seeing holes where the decay occurs.
When there is decay there could be a mild to severe pain in the tooth. This pain can be especially noticeable when you bite down.
Sometimes there are no visible signs of tooth decay. You might not experience pain, sensitivity or any such visible symptom.