It’s not always possible to identify a trigger, but the following things may cause migrainous headaches in some people:

• Dietary factors- cheese, chocolate, red wine, citrus fruits, and foods containing an additive called tyramine.
• Excessive dieting.
• Psychological factors- stress/anxiety, depression and sleep disturbances.
• Environmental triggers- bright lights, loud noises or strong smells.
• Medications- for example HRT and the contraceptive pill.
• Menstruation and the menopause.