What should I do if I have a headache from a toothache? Toothache headache should be clarified whether the headache is caused by odontogenic or trigeminal nerve. If the headache is caused by dental disease, the patient can go to dentistry to check the inflammation around the teeth or the pulp, and then go for dental X-ray or blood test, and there are also tests that clearly indicate the presence of infection. Anti-infective medication, such as cephalosporin antibiotics or metronidazole, can be given to treat the headache after the inflammation of the tooth is controlled. If the toothache or headache is caused by damage to the trigeminal nerve, the pain in the face and head is mainly due to the lesions of the first and second branches of the trigeminal nerve. In this case, the main treatment is to give pain medication, such as carbamazepine, pregabalin or gabapentin orally to control the symptoms, so it is necessary to clarify whether the headache is caused by the toothache or the headache is caused by the trigeminal nerve itself.