The causes and triggers of heachaches are wide and varied but one common cause is referred pain from the neck and upper back. A report released in 2001 by researchers at the Duke University Evidence-Based Practice Centre in the USA found that spinal manipulation resulted in almost immediate improvement for those headaches that originate in the neck, and achieved at least similar and in many cases better pain relief than use of medication.
Your chiropractor may in these cases liase with your GP to perform any appropriate tests to rule out other sources of headaches to assist diagnosis of headaches originating from the neck before proceeding with treatment.