Toothache with pain on the left side of the nose may be due to endodontitis, periapical inflammation, trigeminal neuralgia, and so on. 1. Periapical periodontitis: After some patients develop periapical periodontitis, the inflammatory secretions from the tissues around the root tip ooze out, which may lead to the symptoms of toothache, and at the same time, it also produces pulling pain in the nose. This situation generally occurs in the anterior teeth. 2. Pulpitis: The pain of acute pulpitis may radiate to other parts of the tooth, and some patients may have pain on one side of the nose. 3. Trigeminal neuralgia: Excluding diseases of the teeth themselves, this condition may also be trigeminal neuralgia, and patients may experience toothache involving nose pain. Trigeminal neuralgia usually has trigger points and is often mistaken for a toothache when the pain flares up, requiring medical examination and treatment. If the pain symptoms occur frequently, it is recommended to seek medical examination and treatment.