The medical community has identified a set of well defined headache categories. The first category, that of the primary headache, is experienced by almost everyone throughout their lives. The primary headache occurs more frequently than any other kind of headache. The cluster headache category causes far more pain and affects only a small segment of the population. Cluster headaches earn their name from the random grouping of attacks that they present with. Patients can go without an attack for years at a time before suddenly experiencing a rash of cluster headaches. Secondary headaches are classified as symptoms of a deeper neurological issue, such as internal bleeding, tumor growth, or chemical imbalance in the brain. Cluster headaches and secondary headaches occur on a much less frequent basis than primary headaches.

The common stress headache falls into the primary category. Although not life threatening, the stress headache can become an impediment to the enjoyment of daily life