Updated on February 1, 2024
6 min read

The 7 Symptoms of a Cavity

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7 Symptoms of a Cavity

Cavities can take months or even years to spread to the dentin and/ or pulp, causing symptoms like:

  1. Tooth sensitivity (to hot, cold, and sweet foods and beverages)
  2. Tooth pain (mild to severe pain when eating or drinking)
  3. Toothache (mild to severe pain when you are not eating)
  4. Changes in tooth color 
  5. Visible holes or pits 
  6. Bad breath 
  7. Bleeding gums 

According to Dr. David Chen, DDS, “the symptoms of dental cavities will vary depending on the stage of the cavity and size of it. For small cavities in the early stages, there are usually no symptoms, which is why most people are unaware that they even have them.” 

“For medium sized cavities that have grown beyond the enamel and into the dentin of the tooth, patients will start to feel sensitivity to either sweet, cold, or hot,” he adds. “For large cavities that have grown beyond the dentin and into the nerve of the tooth, symptoms such as a constant dull ache or a throbbing pain becomes common.”

Therefore, Dr. Chen says seeking out early treatment is not only a wise health decision but also a great financial decision. Your future self will thank you for taking care of cavities early.

When to See a Dentist for a Cavity

Dental professionals recommend regular dental checkups and cleanings to catch tooth decay early. 

You should see a dentist if you experience any symptoms, including:

  • Bleeding gums
  • Tooth or mouth pain
  • Tooth sensitivity
  • Visible holes or dark spots on the tooth 
  • Bad taste in your mouth
  • Swelling of your mouth or face (this is a sign of infection)
  • Difficulty chewing

What is a Cavity?

Teeth are made of three primary layers: enamel (hard outer layer), dentin (soft middle layer), and pulp (root with nerves and blood supply). 

Tooth cavity illustration

A cavity, also called tooth decay or dental caries, is a hole caused by bacteria that starts in the enamel. If left untreated, it can progress to the dentin and pulp and ultimately cause infection, pain, and tooth loss. A cavity will not go away on its own. 

The natural bacteria in your mouth feed off the food you eat, creating acidic byproducts and dental plaque (a sticky coating). When food sits on the teeth for long periods of time, the acid starts to decay the enamel, causing a hole. If the hole is not repaired, the decay can progress into the dentin and pulp, causing sensitivity, pain, and/ or infection. 

There are three types of cavities:

  1. Smooth surface cavity is decay that forms on the smooth surface of a tooth
  2. Pit and fissure cavity is decay that forms on the chewing surfaces of a tooth
  3. Root cavity is decay that forms on the root of the tooth under the bone and the gums

Cavities can develop in both the front teeth and back teeth, depending on various habits. They usually start off as white spots and progress into yellow, brown, or black holes. 

Cavities are a common health concern, with over 90% of adults having at least one cavity in their lifetime. Over half of children between the ages of 6 and 8 have had one or more cavities in their baby teeth.1 

What Causes Cavities?

Bacteria thrive off the sugar particles left on teeth after eating and drinking. One of the byproducts of bacteria is acid, which erodes tooth enamel over time.  

If a dentist does not treat a cavity in the enamel, the tooth decay can spread to the tooth’s inner layers, causing pain and dangerous infection that can travel to other parts of the body.

Common risk factors associated with the formation of cavities include:

  • Sugary/acidic foods and beverages
  • Dental plaque build-up (sticky film caused by bacteria byproducts that leads to tooth decay)
  • Frequent snacking 
  • Lack of good oral hygiene (not brushing or flossing regularly)
  • Bedtime breastfeeding or bottle feeding 
  • Lack of fluoride  (a mineral added to water that is known to prevent cavities)
  • Dry mouth (saliva helps prevent cavities)
  • Heartburn (stomach acid can damage tooth enamel)
  • Eating disorders (bulimia can lead to tooth decay)


During a routine dental exam, the dentist will take X-rays and look in your mouth for visible signs of cavities and gum disease. 

According to Dr. David Chen, an early cavity is nearly undetectable to the naked eye and dental X-rays. It is not until the cavity achieves approximately 30% of tooth demineralization that it starts to appear on X-rays. Once it reaches this threshold, dentists can detect a visual change in the enamel to one of two colors, white or brown. As the cavity progresses, it turns into a darker shade of brown until it forms a cavitation or hole in the tooth.

Treatment Options 

Because a cavity can’t heal on its own, it needs to be treated promptly. In the early stages, prescription-based fluoride toothpaste can help slow decay progression. 

Treatment will depend on the type of cavity and tooth location. Common options include:

  • Dental fillings fill cavities into enamel and dentin with various materials (silver, gold, composite resin, glass ionomer)
  • Root canals are needed if the cavities reach the pulp; it involves removing the pulp from the affected tooth, taking out the nerve endings that cause pain, and replacing it with artificial pulp and a dental crown 
  • Tooth extraction removes the entire tooth if the cavity has progressed to the point where the tooth can no longer be replaced; there are several tooth replacement options 


If left untreated, cavities can cause irreversible tooth damage, resulting in tooth loss. 

The tooth decay process can also cause difficulty eating, severe pain, and infection. A tooth abscess (or pocket of pus) can form and spread to other areas in the body. An untreated abscess can be fatal. 

Prevention Tips

Oral health is a critical part of overall health. Regular dental checkups are recommended to prevent cavities. 

Other tips on preventing tooth decay include:

  • Brush your teeth with a fluoridated toothpaste at least twice a day
  • Avoid sugary foods and drinks
  • Floss daily to remove plaque build-up
  • Get dental sealants to protect the chewing surfaces of teeth
  • Limit snacking between meals
  • Drink fluoridated tap water 


Cavities are holes in the teeth caused by bacteria that produce acids. They start as small white spots on teeth that turn darker as they progress into the dentin and pulp. 
Because oral health is directly linked to physical health, an infection caused by a cavity can spread to the rest of your body. It’s recommended to get regular dental checkups and cleanings. Visit a dentist sooner if you experience pain, tooth sensitivity, or difficulty chewing.

Last updated on February 1, 2024
5 Sources Cited
Last updated on February 1, 2024
All NewMouth content is medically reviewed and fact-checked by a licensed dentist or orthodontist to ensure the information is factual, current, and relevant.

We have strict sourcing guidelines and only cite from current scientific research, such as scholarly articles, dentistry textbooks, government agencies, and medical journals. This also includes information provided by the American Dental Association (ADA), the American Association of Orthodontics (AAO), and the American Academy of Pediatrics (AAP).
  1. Cavities.” Centers for Disease Control and Prevention. 
  2. Tooth decay.” National Institute of Dental Craniofacial Research.
  3. Cavities.” Merck Manual.
  4. Cavities: What are they and how do we prevent them?” American Dental Association.
  5. The tooth decay process: How to reverse it and avoid a cavity.” National Institute of Dental Craniofacial Research.
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