Migraine is irregularly episodic, so there needs to be some explanation for why a particular migraine episode occurs at a particular time and not at another time, the cause is unknown. Family history is present. Clinically many cases of migraine present their maternal and paternal inheritance, However the risk factors and precipitating factors "Migraine Triggers" can be explained.

      A migraine trigger is any factors that on exposure or withdrawal lead to the development of an acute migraine headache. Triggers may be categorized as behavioral environmental, infection, dietary, chemical, or hormonal.

Enviournment
      Several studies have found some migraines are triggered by changes in weather. Temperature mixed with humidity. High humidity plus high or low temperature was the biggest cause. Significant changes in weather and changes in barometric pressure also predispose the factor.

Hormonal influence
      Great female preponderance, Attacks exacerbated during menstrual cycle, pregnancy, Oral Contraceptive usage, estrogen therapy and menopause. Although the exact relationship between hormones and headaches isn't clear, fluctuations in estrogen and progesterone seem to trigger headaches in many women with migraine headaches. Women with a history of migraines often have reported headaches immediately before or during their periods. Others report more migraines during pregnancy or menopause. Hormonal medications, such as contraceptives and hormone replacement therapy, also may worsen migraines.

Dietary precipitants
      Certain foods appear to trigger headaches in some people. Common offenders include alcohol, especially beer and red wine; aged cheeses; chocolate; fermented, pickled or marinated foods; aspartame; caffeine; monosodium glutamate - a key ingredient in some Asian foods; certain seasonings; and many canned and processed foods. Skipping meals or fasting also can trigger migraines.

Psychological stress
      Especially after period of stress like weekend. A period of hard work followed by relaxation may lead to a weekend migraine headache. Stress at work or home also can instigate migraines.