Headache What is a headache? Headache is defined as pain in the head that is located above the eyes or theears, behind the head (occipital), or in the back of the upper neck. Headache,like chest pain or dizziness, has many causes. What are the causes of headaches? There are two types of headaches: primary headaches and secondary headaches.Primary headaches are not associated with (caused by) other diseases. Examplesof primary headaches are migraine headaches, tension headaches, and...