The pain of cluster headaches is described as one of the worst pains ever experienced. It starts quickly, without warning, and reaches a crescendo within fifteen minutes. It is deep, non-fluctuating, and explosive in quality. In addition, 10 to 20 percent of patients can have paroxysms of stabbing, icepick-like pain around the eye that lasts for a few seconds. The symptoms resolve in one to two minutes. This pain is usually described very eloquently by patients: “It feels like a hot poker pushing into my eye,” or “It feels like someone is stabbing my eye with a sharp knife.” The pain is always on one side, and generally affects the same side in subsequent bouts. Typically, this type of headache may cause you to awaken suddenly from the pain.