Cluster headache

Cluster headache is far less common than migraine headache or tension headache. Cluster headaches begin far more dramatically, however, and remain quite unique in their course over time.
As the name suggests, the cluster headache exhibits a clustering of painful attacks over a period of many weeks. The pain of a cluster headache peaks in about 5 minutes and may last for an hour. Someone with a cluster headache may get several headaches a day for weeks at a time - perhaps months - usually interrupted by a pain-free period of variable length.
In contrast to people with migraine headache, perhaps 5-8 times as many men as women have cluster headache. Most people get their first cluster headache at age 25 years, although they may experience their first attacks in their teens to early 50s.
You can get 2 types of cluster headache:

• Episodic: This type is more common. You may have 2 or 3 headaches a day for about 2 months and not experience another headache for a year. The pattern then will repeat itself.
  
  
• Chronic: The chronic type behaves similarly but, unfortunately, you get no period of untreated sustained relief.

Cluster Headache Causes

No one knows exactly what causes cluster headaches. As with many other headache syndromes, theories abound, many of which center on your autonomic or "automatic" nervous system or your brain's hypothalamus. These systems play a role in rhythmic or cyclical functions in your body. The involvement of either system in the syndrome would account for the periodic nature of the headache.

• Many experts believe that cluster headache and migraine headache share a common cause that begins in the nerve that carries sensation from your head to your brain (trigeminal nerve) and ends with the blood vessels that surround your brain.
  
  
• Others believe that the pain arises in the deep vascular channels in your head (for example, the cavernous sinus) and does not involve the trigeminal system.

Cluster Headache Symptoms

The pain of cluster headache is its defining and most dramatic feature. This pain comes on without warning (no forewarning symptoms such as the aura in classic migraine) and may begin as a burning sensation on the side of your nose or deep in your eye.
The pain peaks in just a few minutes. People describe the feeling as having an ice pick driven through your eye. They use words such as "excruciating," "explosive," and "deep." This stabbing eye pain carries with it a rapid electrical-shocklike element, which may last for a few seconds, and a deeper element that continues for a half-hour or longer. The pain almost always begins in your eye and always on 1 side of your face. Interestingly, for most people the pain stays on the same side of the face from cluster to cluster, while in a small minority the pain switches to the opposite side during the next cluster.
In addition to its one-sidedness, other characteristics separate cluster headaches from other headaches.

• The headaches commonly come on just after you go to sleep.
  
  
• Often the eye on your affected side will tear.
  
  
• Your eyelid on the affected side will droop.
  
  
• You will experience one-sided nasal stuffiness and runny nose. 

http://www.emedicinehealth.com/cluster_headache/page3_em.htm