1.Gender and age: the age is more than 40 years old, with more middle-aged and elderly people. There are more women than men, about 3:2. 2. Pain site: more on the right side than on the left side, the pain starts from a point of the face, mouth or jaw and spreads to one or more branches of the trigeminal nerve, with the second and third branches being the most common, and the first branch is rare, only ~%. The pain does not extend beyond the midline of the face or the trigeminal nerve distribution area. Occasionally, there are bilateral trigeminal neuralgia, accounting for 3%, mostly alternating pain on both sides, and simultaneous attacks of bilateral concordance are rare. 3.The nature of pain: such as inverted cutting, pins and needles, tearing, burning or electric shock-like severe and unbearable pain, or even painful. 4, the regularity of pain: the attack of trigeminal neuralgia is often without warning, while pain attacks are generally regular. Each pain attack lasts from only a few seconds to 1 to 2 minutes and stops abruptly. At the beginning of the disease, the number of attacks is small and the interval is long, ranging from several minutes to several hours, but with the development of the disease, the attacks become more frequent, the interval is gradually shortened, and the pain is gradually aggravated and intense. The pain attacks decrease at night. There is no discomfort during the interval. 5, triggering factors: talking, eating, washing, shaving, brushing teeth and wind blowing can trigger a pain attack, so that the patient is on tenterhooks, depressed, careful and cautious actions, and even afraid to wash their faces, brush their teeth, eat, and speak carefully, for fear of causing an attack. 6, trigger point: trigger point is also known as “ trigger point ”, often located in the upper lip, nose, gums, corner of the mouth, tongue, eyebrows and so on. Light touch or stimulation of the trigger point can stimulate the onset of pain. 7, expression and facial changes: the attack often suddenly stop talking, eating and other activities, the pain side can present spasms, that is, “painful spasms ”, frowning and clenching teeth, open mouth to cover the eyes, or use the palm of the hand to rub the face so that the local skin roughness, thickening, eyebrow hair loss, conjunctival congestion, tears and salivation. The expression is mental tension and anxiety. 8, neurological examination: no abnormal signs, a few have facial hypesthesia.