Hi there...causes of headache are many like fatigue, sleep deprivation, stress, the effects of few medications, the effects of recreational drugs, viral infections, common colds(most common cause of headache), head injury, teeth or sinus diseases, refractive error, any bleeding in brain or infection or tumors of brain, nerve compression in neck. Treatment of headache depends on type of headache. Lifestyle changes, relaxation exercises, sleeping atleast 6-7hours per day, healthy food habits, avoid smoking,recreational drugs,alcohol, avoid stress environment. You can go for counseling if you have any personal issues causing you headache.. Nsaids like paracetamol, diclofenac can help you. But avoid taking too many tablets as they can affect your health..