“Do I Need A Root Canal?” – Symptoms To Look Out For

Root canal treatment (RCT , also known as endodontics) is needed in the case of irreversible damage to the tooth nerve. This damage is caused by decay or trauma to the nerve. But how can you and (more importantly) your dentist tell if you need this done?

Your dentist will firstly ask you about any pain and other symptoms you might have, and then look in your mouth for any signs of needing root canal…


Abscess on gum above a front tooth.

An abscess on gum above a front tooth, which needs RCT

Root canal symptoms that may indicate the need for this work include:

  • Severe tooth pain, often this persists for some time and possibly interrupts your sleep. This pain may be due to the pulp dying off or an abscess forming at the tip of the offending tooth. There are few things in life that are as painful as a toothache, like this, that keeps you awake all night!
  • This pain may radiate out to the ear, temples or jaw areas.
  • Pain on biting down onto or touching the tooth. This is due to inflammation or infection at the root tip, felt when the tooth is pressed down into it’s socket – thus irritating the root area.
  • Swelling, or a ‘pimple’ on the gum (see image). This may be discharging pus, which can cause a bad smell or taste.
  • Sensitivity to heat, a classic sign of the pulp being damaged irreversibly.
  • Tooth sensitivity to cold, that remains after the stimulus has gone., e.g a cold liquid. This is in comparison to classic sensitivity which is fleeting and is gone once the stimulus has been removed.
  • A tooth that is darker than those beside it (see image below). This occurs with ‘dead’ teeth.
  • A tooth is severely broken down. There may be signs of the damage that is causing the toothache. That is, signs of decay (ie a cavity), a broken tooth or cracked tooth symptoms.

However, as explained below, there may actually be no symptoms and yet you may still need a root canal.

See here for tips on dealing with toothache.


"Image of a dental xray showing a large abscess needing root canal"

A dental X-ray showing a large abscess (the dark circle) which needs RCT


Root Canal Symptoms: What Your Dentist Will Look For

Your dentist can judge if you need a root canal based on any symptoms you have and a few simple observations and tests. The aim is to discern if your problems necessitate RCT, or if the damage is reversible without it (ie ‘reversible pulpitis‘), in which case a filling may suffice.

These observations include checking the condition of the tooth and any dental work done on it, and the color and the condition of the gum around it. The dentist will also usually need to take an X-ray, in order to look for any signs of infection. A periodontal, gum abscess may cause similar symptoms so this must be ruled out.


The tests used by a dentist to check if you need RCT will include:

  • Applying heat and cold to the tooth, to check the health of the nerve.
  • Tapping the tooth, or getting you to bite down on something. As noted above, one that needs RCT will often be tender when touched.
  • Using a special device called an electronic pulp tester, another way of checking the vitality of the nerve.

Sometimes a root canal is needed on a tooth that currently has no symptoms. It is common that a routine dental x-ray may pick up a ‘silent’ abscess in the peri-apical area. This indicates nerve damage to the tooth in question.

"Image of an obvious root canal symptom, dark teeth"

An obvious sign.. These darkened teeth got damaged with a knock several years previous.

So, a pulpal nerve may die off and an infection form without the patient being aware of it! Or there may have been mild symptoms when the nerve was dying off, but not enough to make one attend the dentist. The dead tooth (read more) is best treated to prevent future problems, even if it has no current root canal symptoms.


Here’s a useful video from ehow that further explains the problems you may get.



If you do need a root canal, see more here on does RCT hurt?  What is involved in the procedure?

Want more advice on the treatment in general? See our guide to dental root canals.

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