Tension headaches are often caused by issues with the neck and upper spine. If the spine becomes subluxated, this will cause nerve irritation which makes the surrounding muscles tighten up, leading to headaches. Subluxations can happen in many different ways: poor posture, “holding” stress in the shoulders, lifting something the wrong way, sports injuries, etc. This is not just an issue of tight muscles! Unless the nerve interference is removed with a chiropractic adjustment, the muscles will not be able to fully relax.