External stimuli
Cold, dry weather, High temperatures together with high humidity, Föhn wind, Changes in weather with sharp changes in temperature, Sharp increase or decrease in air pressure (for example in aircraft), Glaring light, High noise levels, Strong odours: heavy perfume, solvents

Physiological triggers
Irregular and insufficient sleep, Changed sleep patterns at the weekend or on holiday, especially too much sleep ("week-end or holiday migraine"), Irregular meals, Missing breakfast, Late nights, Physical overexertion: carrying heavy weights, walking too quickly or running, intensive training without slowly warming up beforehand, Too hot showers or baths, Jetlag after long flights, Smoking, Certain foods and drinks: alcoholic drinks, especially red wine, drinks containing caffeine, especially coffee, (mature) cheese, fatty foods such as sausage, ham and salami, eggs, beans, onions, seafood, chocolate, citrus fruit,

nuts, gluten in wheat flour, nitrites in meat, fish and additives such as glutamate (Asian cooking), Therapeutic fasting, A large number of medicines, Hormone changes (e.g. caused by menstruation), The pill (contraceptives)

Psychological triggers
Worry, Anxiety, Stress or anticipation of stress and the release from stress, Perfectionism, Depression, Shock, Grief