Hi thanks for your question.
Exact cause of mgraine is not known. Gentic and envirnmental factors play a role.It is caused by changes in the brainstem and its intractionan with trigeminal nerve
.Imbalance in brain chemicals including serotonin which play important role in nervous system.There is decrease in serotonin level during attack which trigers trigeminal system to release a substance called as neuropeptides which travel to brain coverings callesd meninges causing headache.
Hormonal factors in women ,certain foods (choclates cheese and alchol) ,stress and sensory stumli (bright light) environmental factrs (change in tempture) ,excessive exertion,lack of sleep,and certain drugs like oral contraceptive pills
triggers the attack.
Treatment includes avoiding the triggering factors described above and drugs.Two types of drugs are prescribed to trean migraine.One to treat the symptoms like acetaminophen
,ibuprofen and ergot .Second group of drugs to prevent an attack which include beta blockers and antidepressant Dyspepsia
and gastritis could be due to gall stones
Hope this answers your question