Does having tooth sensitivity mean you need a root canal?

Not always: Some tooth sensitivity can be normal; however, prolonged sensitivity to hot temperatures or tapping on your teeth can be signs that the tooth is abcessed and needs a root canal. Momentary sensitivity to cold water or air can sometimes be expected.

Not necessarily: Tooth sensitivity does not usually require a root canal in order to effectively treat it. There are many procedures that precede a root canal that can be used to treat the sensitivity. Most commonly, you should use a desensitizing toothpaste such as sensodyne and a Fluoride mouthwash. Usually this works. In cases of extreme sensitivity you may require a root canal.