75% of pain is caused by trigger points (areas of contracted cells in muscle tissue), but they are drastically under-diagnosed as the source of pain, including headaches and migraines. Trigger points may refer pain and other symptoms both in the local area and/or to other areas of the body, but since over 74% of trigger points are not located in the area where you feel pain, treating the local area does not resolve the problem most of the time. The most common "referral patterns" have been well documented and diagrammed over decades of research.
Probably at least 90% of headaches and migraines are caused by trigger points in the upper back, neck, scalp, and facial muscles. You can probably relieve much or all of your headache pain with a combination of trigger point self-help, and identifying and eliminating all the perpetuating factors to the extent possible (the things that cause and keep trigger points activated).
TMJ pain is often occurs together with headaches and migraines, and it is essential to treat both for lasting relief. In addition to headaches, migraines, and TMJ pain, conditions such as trapezius pain, neck stiffness and lack of range of motion, head-forward posture, and improper breathing are addressed.
Chapters 6 through 16 have illustrations of muscles that may harbor trigger points that are the source of your pain. You’ll find illustrations of common pain referral patterns that you can compare with your symptoms, and this will help you figure out where the common trigger points causing your pain are likely located. Along with outlining the common symptoms and causes for trigger points for each muscle, there are lists of "helpful hints" for resolving trigger points. Self-help techniques are written out and accompanied by detailed photos to guide you through the techniques.
An extensive Appendix on perpetuating factors that will cause trigger points to form in any of the muscles of the body will help you gain lasting relief.