There are several easy answers to the question, “Why do teeth hurt?”  For example, teeth hurt because you don’t take care of them.  But, that’s not what I want to talk about in this article.  I want to talk about why it is that teeth hurt so much.  They’re so small, yet if you’ve ever had a toothache that kept you up at night, you know that teeth can hurt almost as much as any other feeling of pain you’ve ever felt.

Teeth Hurt Because They Are So Hard

Teeth hurt because they are so hard.  When the tissue inside of the tooth (the pulp) gets hurt, it has no room to expand.  Here’s an example.  Let’s say someone punches you in the shoulder.  Your shoulder might get warm and swollen.  Your shoulder has room to get bigger.

Now let’s say that someone punches your tooth and chips the bottom of it.  The force of the blow will likely irritate the pulp of your tooth and cause it to get warm and swollen.  Here’s the problem, when the pulp gets swollen, it wants to get bigger, but there’s nowhere to go!  The pulp is encased in a hard shell known as the dentin and enamel of your tooth.  Pressure builds up inside of your tooth.  Suddenly, the tooth that was hurting due to the initial trauma is now also hurting because of the pressure.

Not sure what the difference between pulp, dentin, and enamel is?  Read my article about the anatomy of a tooth.

Here is what happens in technical terms when the pulp becomes inflamed.  It’s a quote taken from the book, Cohen’s Pathways of the Pulp by Hargreaves:

Inflammation in the pulp takes place in a low-compliance environment composed of rigid dentinal walls. Compliance is defined as the relationship between volume (V) and interstitial pressure (P) changes: C = Δ V/ Δ P. Consequently, in the low-compliant pulp, an increase in blood or interstitial volume will lead to a relatively large increase in the hydrostatic pressure in the pulp. The acute vascular reactions to an inflammatory stimulus are vasodilatation and increased vascular permeability, both of which will increase pulp interstitial fluid pressure and may tend to compress blood vessels and counteract a beneficial blood flow increase.

Other Parts of Our Body Experience Similar Pain Levels

The dental pulp isn’t the only tissue that experiences high levels of pain when it is inflamed.  Most places in the body that are enclosed in a rigid structure experience lots of pain.

This is why headaches can be so painful, the skull is rigid and there’s no room for the swelling to go.

Another example is when you smash your fingernail and you get lots of inflammation underneath the fingernail.  Some people have even gone so far as to burn or poke holes through their fingernails to relieve the pressure that builds up.

Conclusion

Teeth hurt because when the pulp gets even slightly injured, it wants to expand and there’s no room for it to expand.

Do you have any questions related to tooth pain?  Leave them below in the comments section.  Thanks for reading!