A friend has had migraine attacks for the past week each evening what might be the cause?

Migraine Triggers: A variety of external and internal factors can trigger a migraine attack in certain individuals who may have a genetic or neurochemical predisposition to migraine. External triggers such as weather-related changes, high humidity, high altitude, sensory input such as glaring or flashing lights, sunlight, loud noises, and exposure to odors, head trauma, and stress. See OFP specialist.