Other than the migraine headache, which is completely different, common headache is a symptom of a basic systemic cause or problem. A large number of causes for headache exist and almost each has a different cause. The pain we experience is not produced in the brain matter inside the skull but it is felt by the sensitive coverings of the brain. Organs like ear, tooth and sinus produce headache when they radiate pain to these coverings when they are tense.