Likely causes for migraines are:-
Some people who suffer from migraines can clearly identify triggers or factors that cause the headaches, but many cannot. Potential migraine triggers include:
Allergies and allergic reactions
Bright lights, loud noises, and certain odors or perfumes
Physical or emotional stress
Changes in sleep patterns or irregular sleep
Smoking or exposure to smoke
Skipping meals or fasting
Alcohol
Menstrual cycle fluctuations, birth control pills, hormone fluctuations during menopause onset
Tension headaches
Foods containing tyramine (red wine, aged cheese, smoked fish, chicken livers, figs, and some beans), monosodium glutamate (MSG), or nitrates (like bacon, hot dogs, and salami)
Other foods such as chocolate, nuts, peanut butter, avocado, banana, citrus, onions, dairy products, and fermented or pickled foods.
Triggers do not always cause migraines, and avoiding triggers does not always prevent migraines.
Dehydration could cause them too as can low blood sugar levels.