Our face has two separate trigeminal nerves, one on each side. These nerves carry pain signals and other sensations to our brain. If for any reason, the nerve is damaged, it can cause a lot of pain. For example, if you start brushing your teeth or shaving, it triggers the trigeminal nerves, which sends pain signals to your brain.
In the beginning, you will have mild sensation, but with time the pain grows, and so does the duration. Then the frequency of these attacks increases. It works in cycles, so you might feel pain for two weeks, and then it is over for a few days before it comes back again. It is diagnosed clinically and there are various treatment options which includes medications and pain management injections.
For more information, consult Dr. Stanley O Ikezi, an experienced Double Board Certified Pain Management Specialist in New York City.