5 Potential Signs You Have a Cavity

Over 80% of Americans have at least one cavity by the time they turn 34 years old1. If that statistic sounds alarming, you can take some solace in knowing that tooth decay is avoidable with preventative dental care. It’s also very treatable with early identification and diagnosis. However, many people have cavities and don’t know it or don’t get treatment — the CDC estimates one in four adults in the U.S. have untreated cavities2. These statistics demonstrate the importance of knowing the signs of a cavity, and we’re here to help you out! 

This guide will help you learn the signs of a cavity to look for so you can avoid more serious consequences, such as an abscess or tooth loss.

Why cavities develop

Plaque is a sticky film of bacteria on your teeth caused by food, drinks, and saliva. If it isn’t removed via brushing, flossing, and regular dental checkups, it can wear down the hard layer of enamel that protects your teeth. Bacteria and acids can then form small holes in the tooth, which is a cavity3. This deterioration can continue down to the tooth pulp and ultimately result in tooth loss if it isn’t addressed4.

Potential signs of a cavity

Small cavities may not have any symptoms at all4, which is why your biannual dental exams are so important. The early stages of tooth decay may cause white spots due to mineral loss5; however, they’re tough to spot without a trained eye.

As a cavity progresses, you may experience some of the following noticeable symptoms. Note that these are not definitive signs of a cavity — always consult with your dentist!


Toothache or sensitivity

This is usually the most obvious sign of a cavity. When holes form in enamel, they expose the underlying dentin. Dentin contains tissues that connect to the tooth’s nerves. When the dentin is exposed, it gets irritated by bacteria in your mouth and can potentially cause sensitivity or sharp, shooting pain. A variety of factors can exacerbate the discomfort, including hot, cold, or sweet foods and drinks, cold air, chewing, and brushing your teeth6. If a cavity worsens, mouth bacteria will weaken the dentin and make its way to the pulp where the tooth’s tissues and nerves live. This often results in severe pain and can develop into an abscess if it isn’t treated quickly7.

Sensitivity and pain don’t necessarily mean you have a cavity. Some people have naturally thin enamel, and others can wear theirs down if they grind their teeth or brush too hard6. Cold and sweet foods can cause sensitivity if your gums are receding and exposing the tooth’s root8, another issue that requires professional treatment. You can also experience sharp pain when a tooth is cracked or chipped. But when the sensitivity or pain is isolated to one tooth and you haven’t experienced a dental injury, it’s more likely to be caused by tooth decay6.

Visible holes in teeth

In some cases, the holes formed in your teeth by bacteria are difficult to see, whether it be due to their location (e.g., between the teeth) or size. But as more of the enamel deteriorates, it may form a hole large enough to see with the naked eye9.

Dark stains

Certain foods and beverages, tobacco, and aging can all stain your teeth. However, tooth decay is another potential cause. This isn’t the cavity itself — it’s the dentin, which is usually yellow, gray, or brown11. Dentin may become visible when enough enamel wears away due to a cavity10.

Bad breath

Bacteria, not cavities themselves, are the primary cause of bad breath. But since cavities form holes in your teeth that your toothbrush can’t reach, they provide a place for bacteria to build up. The result can be halitosis, or chronic bad breath11. In severe cases, bacteria can kill the pulp underneath the dentin, which can also cause bad breath12.

Swelling or bleeding gums

Plaque buildup can cause inflammation along the gumline, leading to swelling and bleeding. While these issues are often signs of gum disease, it can also signal a potential cavity — especially if the symptoms are localized around one tooth13.

How dentists treat tooth decay

For most minor cavities, your dentist will recommend a filling to seal off the cavity and prevent it from spreading. You may need a root canal for more serious tooth decay. Check out these other blog posts to learn more!


For informational purposes only and not intended to be relied on as complete information, or to be construed as tax, legal, investment or medical advice. This is not a sale of or an offer to purchase a benefits plan from Beam. For more information on benefits plans, contact quotes@beam.dental.

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Matt Wilkes

Author Matt Wilkes

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