In short: Common signs you may need a root canal include lingering pain to hot or cold, severe toothache, pain on biting, a pimple-like bump on the gum, swelling, tenderness, or a tooth that has darkened. Some infected teeth cause no symptoms at all, so a dentist’s exam and X-ray give the real answer.
A root canal is needed when the nerve inside a tooth (the pulp) becomes infected or badly inflamed. Certain signs point to this, though only a dentist can confirm it:
- Lingering sensitivity to hot or cold — pain that stays for many seconds or minutes after the hot/cold is gone, rather than a quick twinge, suggests the nerve is inflamed.
- Severe or spontaneous toothache, sometimes throbbing, or pain that wakes you at night.
- Pain when biting or chewing, or when you touch the tooth.
- A pimple-like bump on the gum near the tooth (a sign of an abscess draining), which may release a bad taste.
- Swelling of the gum or face, and tenderness.
- A tooth that has darkened or discoloured compared to its neighbours.
- A deep cavity or a cracked tooth, or a large existing filling.
Importantly, some teeth with a dying or dead nerve give no symptoms and are only found on a routine X-ray — which is one more reason regular check-ups matter.
If you notice any of these, don’t wait for it to worsen into a painful abscess. A dentist will test the tooth and take an X-ray to decide whether a root canal is needed.
Book an appointment and we’ll assess the tooth — if it’s needed, a root canal treatment can save it and stop the pain.