There are numerous causes of headaches and often, the exact mechanism cannot be identified. One very common cause of tension headaches is rooted in the neck, resulting from muscle tension and trigger points.
At the base of the skull there is a group of muscles, the suboccipital muscles, that can cause headache pain for many people. These four pairs of muscles are responsible for subtle movements between the skull and first and second vertebrae in the neck. The suboccipital muscles commonly become tense and tender due to factors such as eye strain, wearing new eyeglasses, poor ergonomics at a computer workstation, grinding the teeth, slouching posture, and trauma (such as a whiplash injury).
Pain from the suboccipital muscles commonly feels like a band wrapping around the head. Also, tension in these muscles may cause compression of a nerve that exits the base of the skull, and trigger pain that wraps over the head and above the eyes.