I recently flew to Florida on vacation. On the last leg of our plane ride, as we decreasing altitude preparing to land, I felt a sudden, excruciating headache over my left eye. Pain level was an 8 out of 10. I described that it felt like a knife piercing my skull. I've had these 3 times before in the same airplane setting, but they subsided just after landing. It doesn't happen every time. In fact, we landed 3 other times on this trip with no symptoms. This time, however, the pain continued until well after we got home lasting about 5 1/2 hours. The pain level fluctuated between a 3 and 8 the entire time. At times, it was the most painful experience in my life, and nothing relieved it. I am now reluctant to fly again for fear it could happen again. We have plans to fly to Italy next summer. I've read about similar cases except that I've not heard of any of these terrible headaches lasting so long. What can I do to avoid this in the future besides not flying again?