Clinical clues and clinical rules: Primary vs secondary headache

Headache is a common condition, accounting for many specialist office visits annually. International Headache Society classification and diagnostic guidelines are invaluable tools for evaluating the headache patient. These guidelines can be enhanced with clinical clues that aid in determining whether a particular headache is primary or secondary. The secondary causes of pain must be ruled out; some neurological imaging techniques and other investigations have proved more helpful than others in this regard. Fortunately, the vast majority of headaches encountered will be of the primary type. Clinicians often have difficulty distinguishing between the types of primary headache disorders, which is crucial when considering treatment options.