In principle, trigeminal nerve pain can be judged according to its pain range and pain area, because the trigeminal nerve has three forks, so its first, second and third branches can be determined according to its pain site and pain lead-in point, and this clinical site can be seen, and it can be triggered by some clinical examinations, and sometimes it can be triggered according to this site with teeth, gums, and attached gums The pain can be triggered by clinical examination, sometimes by the teeth, gums, and attached gums, and sometimes by facial expressions, such as frowning, or washing the face, depending on its extent. The branches of the trigeminal nerve can be differentiated according to the location described by the patient. Generally this clinical examination can also be done by using some cotton swabs and probes to trigger these pains, so the site of trigeminal neuralgia can be triggered by some clinical examination. It does not have any other physical examination that can check its degeneration. But the MRI can sense a vascular lesion in this area. Then the cause of trigeminal nerve pain can be checked inside the MRI with digital vascular examination.