Research studies have turned up several clues as to the cause of cluster headache, but no answers. One clue is found in the thermograms of untreated cluster patients, which show a "cold spot" of reduced blood flow above the eye. The sudden start and brief duration of cluster headaches can make them difficult to treat; however, research scientists have identified several effective drugs for these headaches.

The antimigraine drug sumatriptan can subdue a cluster, if taken at the first sign of an attack. Injections of dihydroergotamine, a form of ergotamine tartrate, are sometimes used to treat clusters. Corticosteroids also can be used, either orally or by intramuscular injection.

Some cluster patients can prevent attacks by taking propranolol, methysergide, valproic acid, verapamil, or lithium carbonate.Another option that works for some cluster patients is rapid inhalation of pure oxygen through a mask for 5 to 15 minutes. The oxygen seems to ease the pain of cluster headache by reducing blood flow to the brain.

In chronic cases of cluster headache, certain facial nerves may be surgically cut or destroyed to provide relief. These procedures have had limited success. Some cluster headachepatients have had facial nerves cut only to have them regenerate years later.Painful pressure. Chronic high blood pressure can cause cluster headache, as can rapid rises in blood pressure like those experienced during anger, vigorous exercise, or sexual excitement.The severe "orgasmic headache" occurs right before orgasm and is believed to be a vascular headache. Since sudden rupture of a cerebral blood vessel can occur, a cluster headache should be evaluated by a doctor.