Cluster headaches are often said to be the most painful of all headaches. They have been described as "boring," bearing, burning," "like a hot poker in the eye," and as "suicide headaches." The age of onset of cluster headaches is most often between the ages of 20 and 40, and they are more common in men than women at a ratio of 2.1. For many years, that ratio was stated to be 3:1. Researchers theorize that women have long been misdiagnosed because cluster headaches were thought to be so...