Chronic daily headache (CDH) is a descriptive term that encompasses several different specific headache diagnoses characterized by frequent headaches.
Primary chronic daily headache subtypes of long duration (ie, four hours or more) are chronic migraine, chronic tension-type headache, medication overuse headache, hemicrania continua, and new daily persistent headache.
Primary headache types of shorter duration that can be chronic and occur daily are chronic cluster headache, chronic paroxysmal hemicrania, hypnic headache, and primary stabbing headache.
This topic will provide an overview of the subtypes of primary CDH. These headache subtypes are discussed in greater detail individually in appropriate separate topic reviews.
Chronic daily headache (CDH) is not a specific headache type, but a syndrome that encompasses other primary and secondary headaches. The term "chronic" in CDH refers either to the frequency of headaches or to the duration of the disease, depending upon the specific headache type.