Millions of people have headaches regularly. An estimated 50 million people in the United States have long-lasting, recurring headaches. Overall, 15-20% of men and 25-30% of women suffer from headaches. There are a number of causes of headaches. They include neck strain from Forward Head Posture, low blood sugar, dehydration, high blood pressure, temporomandibular joint dysfunction, drug reactions, stress, and fatigue. The majority of headaches are tension headaches (also called cervicogenic). Research shows that 90% of these headaches are caused by subluxations in the cervical spine (misalignments of the vertebrae).