Often headaches, even severe ones are being caused by problems in the neck. These are called "Cervicogenic Headaches". These headaches are referred pain, caused by joint stiffness and irritation to nerves in the upper cervical spine. These headaches will mimic a migraine and can cause severe head pain, visual field disturbances, sensitivity to light, nausea and even a strange taste in your mouth. They can be chronic, persistent and even long lasting. The good news is; they respond very well to chiropractic care.