One of the oddities of cluster headache is that a number of triggering factors trigger cluster attacks only during the cluster period, while in the remission phase patients can expose themselves to such conditions without consequences. The best-known trigger for cluster headaches is alcohol. Interestingly, it turns out that it is not alcohol per se that triggers the individual cluster attacks, but that it also depends on the amount of alcohol consumed. Small amounts of alcohol can be very potent and reliable in generating cluster attacks during the cluster period, while larger amounts of alcohol can partially prevent cluster attacks. Individual case reports describe that by consuming large amounts of alcohol, the remission phases can be prolonged and the triggering of cluster attacks can be avoided. However, this is definitely not recommended. Excessive alcohol consumption causes other serious problems, alcohol addiction and organ damage. We must therefore expressly warn against stopping or prolonging remission phases through alcohol consumption! Effective and tolerable medications are available for this purpose.

A number of other substances are known for their potential to trigger cluster attacks. These include in particular histamine and calcium antagonists such as nitroglycerin. Glare is also given as a trigger factor. Wearing sun protection lenses temporarily during the cluster episode can therefore have a preventative effect.

If a patient is suspected of having a cluster headache and the attack phenomenology is described unclearly by the patient, a single attack can be triggered for diagnostic reasons, for example with a sublingual administration of nitroglycerin, and then recorded prospectively in the presence of the doctor.

Strangely enough, medications that are effective after the cluster attack has begun may not have a preventive effect when attacks are triggered experimentally, for example by alcoholic beverages or nitroglycerin. The reason for this behavior is unknown.