I have had a headache for at least 6 months now, and it's all day long. Why do I have a chronic headache?
Without further information, it's not possible to answer this question. The quality and location of headache symptoms vary. Possible structural or vascular intracranial abnormalities may need to be ruled out with appropriate imaging studies. Cervicogenic headache can arise from sources in the cervical spine, and muscle tension patterns can cause headache, as can TMJ issues. Consultation with a headache specialist is necessary.