Though relatively rare, cluster headaches are regarded as among the most painful conditions known. Though migraines affect about 10% of the population, less than 1/3 of one percent have experienced a cluster headache. The vast majority are fortunate not to have. Many anecdotal reports say cluster headaches are worse than migraines or even child birth.

Often reported as a hot, stabbing pain behind the eye or near the temple, they are characterized by happening at regular times. Cluster headaches tend to occur at the same time of day, last for an hour or less, then disappear to re-occur the next day. This can often go on for months or longer. Unlike migraines, which are sometimes preceded by familiar symptoms such as flashing lights, cluster headaches strike without warning.

The cause isn't known with certainty, but many researchers believe this debilitating condition occurs as a result of an abnormality of the hypothalamus. This small gland plays an important role in regulation of the 'biological clock' and changes in the length of day and other factors can influence its behavior.

One striking difference between migraines and cluster headaches is their gender preference. Of the 28 million Americans who suffer from migraines, nearly three times as many women as men are afflicted. Cluster headaches, however, are far more prevalent among men than women, and usually strike those between 20 and 50 years of age. The ratio of men to women sufferers ranges from 5:1 to 8:1.

A range of treatments are available, but the common ones used to combat ordinary tension or even migraine headaches typically have no effect. Aspirin, acetaminophen and ibuprofen - though near wonder-drugs for other conditions - are usually ineffective.

One treatment that has been tried with some success is the inhalation of pure oxygen for several minutes. This is among the so-called 'abortive' treatments, since it only works after the onset of symptoms.

Another is one common among migraine regimens, a class of drugs called triptans. In order to speed delivery, it's often injected rather than ingested, however. Nasal sprays work quickly, but cluster headaches often produce swelling of the nasal passages, making administering the treatment by that route less effective.

Unfortunately, few preventive or prophylactic treatments are effective. Given the poor understanding of the causes and the rarity of the condition, this shouldn't be surprising. Though there are many treatments on the market, such as the use of CCBs (calcium channel blockers), the results are mixed.

In extreme cases, surgery has been tried and is sometimes effective. Nerve blocks, removal of part of the brain and other neurological procedures are an option as a last resort.

Research continues on this puzzling and horrific condition. But relief can not come too soon for those afflicted.