5 Signs You Might Need a Root Canal

Lingering sensitivity to hot or cold — pain that stays for more than a few seconds after the trigger is removed — is one of the clearest early signs that the nerve inside a tooth is inflamed or infected.

Other signs include a dull, persistent ache when biting down, a small pimple-like bump on the gum near a tooth, and visible darkening of a single tooth compared to its neighbors.

None of these symptoms confirm a root canal is needed on their own — only an exam and x-ray can do that — but any one of them is a good reason not to wait for the pain to get worse before booking a visit.