Is it normal to have a little bubble by the tooth and hot/cold w tenderness after root canal?

Conflicting symptoms: A fistula after a root canal is possible. Hot and cold sensitivity on a root canal treated tooth is rare. Thermal sensitivity probably is an adjacent tooth.

See an endodontist: who is a dental specialist focused on root canal therapy relieving tooth pain and saving natural teeth. Sometimes even after a root canal, the infection continues to grow and you may experience a gumboil and pain. See an endodontist for second opinion.