If you have suffered from headaches of any sort for a long enough time, you may have figured out certain things that seem to bring on an attack. These things are called headache triggers and can come from foods, activities, environmental factors, and hormonal changes. When you are first diagnosed, you may be asked to keep a headache diary- a journal that will help you identify the presence of any triggers.

Trigger is a term describing a system in which a small input turns on a large output. They are not causing the headache, only prompting your body to turn on the disorder that you have. The cause of primary headache disorders is unknown, and as a result, the mechanisms that cause some items to trigger a headache are not understood. Let's say that you know that MSG tends to trigger migraine headaches in you. Why? No plausible scientific explanation is available to explain this correlation. Even further, half of the time, MSG may not give you a headache at all. There is a lack of consistency even in a single migraine sufferer with any trigger. Even if it is a common trigger, MSG certainly does not act as a headache trigger in all migraine sufferers, and many will never identify a single trigger for their attacks. Until migraines and other primary headache disorders are better understood, the association between triggers and the onset of an attack remains

The general belief is that for some headache sufferers, a combination of events and/or items triggers, or turns on, an attack. Of these, food triggers are the most commonly identified. MSG tends to be the biggest culprit, occurring regularly in many restaurant menu items, especially Asian restaurants. MSG also makes an appearance in processed foods such as bouillon cubes, frozen pizza, clam chowder, and potato chips, so check the label before eating or cooking with any item. Nitrates are also implicated as a headache trigger and are commonly found in processed meats like lunchmeat and sausage, but even be found in your local water supply. Beer and red wine, aged cheese, caffeine and caffeine withdrawal, and pickled foods are also common triggers. Chocolate is said to be a trigger, but may in fact be innocent as the consumption of sweets is typical in the prodrome preceding a migraine.

Certain activities and environmental factors are commonly thought to trigger headaches. Eye strain, stress, lack of sleep, poor posture, and skipping meals frequently trigger tension type headaches, but can do the same for migraine and cluster headaches. A change in the weather, temperature, or air pollution as well as traveling at high altitudes may do it as well, prompting many to believe that their migraines are sinus headaches. Even loud noises and strong odors can be triggering events, so think twice before lathering on that perfume. Cigarette smoke is a known trigger, whether you are the smoker or an innocent bystander. This may be due to the nitrates present in cigarettes, the strong order associated with them, or both.

Hormonal changes are the most curious of triggers, and may be the reason why so many more women than men suffer from migraines. Seventy five percent of all migraine sufferers are women, and the headaches tend to lessen after menopause unless the woman goes on hormone replacement therapy. Additionally, pregnancy seems to increase the frequency of migraines. Menstruation and sexual activity are examples of regular hormonal fluctuations that trigger headaches. It is during puberty that most women get their first migraines, the onset of the disorder, and it is believed that the normal hormonal fluctuations occurring during development are the triggering event. Hormonal changes are part of the natural biological process, so why they trigger migraines is a mystery; all other triggers are external and controllable. This internal trigger has led to some of the most promising areas of research into the cause and mechanisms at work in primary headache disorders.