The patient is often a middle-aged male complaining of incredibly painful headaches that are located in the eye region.  The headaches cluster over days or weeks and then end, to appear again several weeks or months later. The headaches last on average 20 minutes and are the most painful feeling the patient has felt. The frequency of attacks is on average several times per day, often at night, lasting of one to several weeks. Recurrence may not occur for months or even years later. There is a possible association with smoking as a trigger and alcohol as an exacerbating factor. There is tearing of the eyes and runny nose on the same side of the headaches. The natural history is for headaches to decrease in frequency and intensity as the patient ages. Avoidance of alcohol and smoking are important in managing cluster headaches.