Why Does my Tooth Hurt?

This page discusses only some of the underlying reasons for toothaches. 

As your dentist, I understand that your aching tooth can be a very annoying and painful experience. I assure you that our office takes a very gentle approach to make you comfortable once again. For most of our patients, the cause of the pain can usually be diagnosed and treated simply. Usually it is better to determine cause of the pain and treat it when the problem is still small! 


Most of us have experienced some type of toothache over the course of our lifetime, and the number of reasons for this discomfort are so great that I can only give an overview of them here. Often, the first idea that comes to mind is "uh oh, I have a cavity." I can assure you that a great number of our patients have happily learned that this was not the case!

Anatomy of a Tooth

To understand the source of a toothache, it is first important to understand the anatomy of a tooth.  Our teeth are living entities, complete with nerves and a blood supply to keep them healthy.  Underneath the enamel of the crowns that we brush is another hard (but more yellow) mineral substance called Dentin. Dentin is composed of thousands of microscopic tubes, which communicate with the nerves inside our teeth.  When these 'windows' are exposed, they produce sensitivity to heat, cold, sweets, or other stimuli.  Such tubes are also prominent in the roots of our teeth since our roots do not have an outer enamel coating! The Pulp of the tooth contains the nerve and blood supply of the tooth which travels in a canal in the root of the tooth. When the nerve becomes inflamed it can become hypersensitive to temperature. Inflammation can have many causes.


Cavities are certainly one way to expose the dentin or the pulp, essentially when bacteria tunnel holes through the enamel of our teeth.  Fracturing enamel or losing an old filling may also expose the tubules, which can cause discomfort.   If you have gum recession, which exposes more of the roots of your teeth, there may be exposure for this reason and often painting a sealant on such teeth is all that is needed!


Our teeth may hurt for other reasons as well and include more extensive causes such as infection, trauma, or mobility.  

We have all heard of dental abscesses and these occur when a tooth gets infected and builds up pressure around the root of a tooth. As with any infection in our body, it is very important to have this treated by a professional. A tooth may also hurt when the blood supply to the pulp is blocked


Trauma comes in many sorts, including long-term self-induced trauma such as Bruxism, or grinding of your teeth. When we grind our teeth, we create forces, which not only wear away the enamel on our teeth, but also can cause gum recession and irritate the tissues and ligaments around our teeth. A bad bite or malocclusion may cause spasm in the jaw muscles or pain in the temporal mandibular joint TMJ.  There are several devices and treatments available which can help alleviate these symptoms as well.  Sometimes mobile teeth can also cause irritation. Stabilizing these teeth (i.e., splinting to adjacent teeth) may be a treatment option. If you have impacted wisdom teeth, their 'movement', or eruption, may also be a cause.

Other sources of toothaches

Teeth are not the only sources of toothaches.  If the ligaments or gums around your teeth are irritated by bacteria, you may be interpreting this as a toothache as well, Gingivitis or Periodontal disease are the cause of this type of pain. A dental cleaning and improved home oral hygiene or more involved treatment may be required.  

Referred Pain

Even less obvious reasons for toothaches include causes of Referred Pain.  This occurs when nerves in other parts of our body are irritated and our nervous system interprets this as a toothache.  Rarely, heart disease or myocardial infarction can create a toothache in lower molars and must certainly be considered by the dentist if no other reasons for a toothache are apparent.  Another example of referred pain is when a patient has an earache due to a spasm in the jaw muscles. Pain in the upper teeth can sometimes come from a sinus blockage!

Office Hours

Monday through Friday by appointment,
Wednesday Open until 7 p.m. 

Noon time appointments available.

Dr. Thomas Kelly

1 St. John St. on the green
North Haven, CT 06473
Phone 203-239-0678
Fax 203-239-2043



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