I get asked that question a good amount of the time. Or, I will tell my clients that neck and shoulder tension may be the cause of their headaches. It's, of course, all in how you word it. As a licensed massage therapist it is out of my scope of practice to diagnose anyone for anything. There are times when neck and shoulder tension do not cause headaches. But for those times that do cause it, here is why:
Tension is defined as the act of stretching or straining, being stretched or strained, suspense, or pressure.
If you were to look at the muscles of the shoulders and neck, you will find these names: scalenes, trapezius, rhomboids, and levator scapulae. And when even one of those muscles (or sets of muscles) are strained, or stretched, or has too much pressure and suspense within its fibers, it will push and/or pull at the other muscles surrounding it.
For example, if you feel a lot of tension or tightness in your trapezius muscles, it will pull at your scalenes. Your scalenes are the small bands of muscles that run along your cervical spine - it connects at the base of the skull and down to the trapezius muscles as the top of your shoulders. And once that pulling starts, it creates even more tension up at the base of the skull, putting pressure on your head. As the pressure increases so does your pain. And oftentimes, pain in the head turns into headaches, and if it gets bad enough, migraines.
Another example: Say you have a knot (an adhesion) within the fibers of your rhomboids. (Your rhomboids are located in the upper shoulder quadrant connecting your scapulae to your spine). That knot may be sitting on a trigger point. If a trigger point is pressured enough, the receptors and synapses are going to shoot the pain up into your neck and into your cranium. Also, that knot could be big enough that it does, in fact, also pull at the trapezius muscles which will then pull at the scalenes which will then pull at your head. It can be a never-ending, vicious cycle if you don't get them worked on enough, or maintain optimal health and well being.
So, how do you maintain optimal health and well being? Well, there is having
good diet, exercise, stretching properly, good posture, learning to deal with stress so it actually doesn't affect you, and massage therapy. Once the muscles can relax the tension disappears. And if they're relaxed enough, that tension won't come back.
It's a beautiful thing, really. :)