It is not clear exactly why cluster headaches occur.
Research has found that during an attack there is more activity in the hypothalamus, an area of the brain that controls body temperature, hunger, and thirst.
It may be that this area of the brain releases chemicals that cause blood vessels to widen, resulting in a greater blood flow to the brain. This may cause the headaches.
Why this would happen is a mystery, but it is true that alcohol, a sudden rise in temperature, or exercising in hot weather may trigger attacks.
The cyclical nature of cluster headaches suggests that they may be linked to the biological clock, which is located in the hypothalamus.
Researchers have found that people who have cluster headaches often have unusual levels of melatonin and cortisol during an attack.
Apart from alcohol, cluster headaches are not linked to the consumption of any foods, and they have not been linked to mental stress or anxiety. Alcohol only acts as a trigger if a person is in the middle of a cluster period.
There may be a link between cluster headaches and some medications, such as nitroglycerin, which is used for the treatment of heart disease.
In northern countries, attacks tend to be more frequent during the fall and spring. Extreme variations in temperature can trigger an episode during an attack. The change in temperature is often linked to a rapid rise in body temperature.
