With headaches and migraines, more so than other musculo-skeletal conditions, there are often multiple other issues at play. I analogize headaches like a pot on the stove. If you have a large pot on the stove and it's filled with a big roast, carrots, onions, potatoes and water and you turn up the heat too high, it will boil over. If you take out the "Big roast" (big roast being the joint complex- tension associated with chiropractic), then you can often tolerate a good portion of the heat without boiling over. The other "triggers" of a headache can be food allergens, stress, hormones and/or other internal struggles (the vegetables).