Chronic daily headache is an umbrella term that
includes 4 primary headache entities:
- Chronic/Transformational Migraine
- Chronic Tension-type Headache
- New Daily Persistent Headache
- Hemicrania Continua
By definition, these headaches occur more than 15 days per month, and one or more of these entities are likely to affect at least 4-5% of the general population.
Because varieties of these conditions, including the term chronic daily headache, have been used so many different ways, this overall category of illnesses has been greatly misunderstood and confused.
The most common of the entities, chronic/transformed migraine, reflects the presence of pre-existent, intermittent migraine attacks which over time have become progressively more frequent until they occur more than 15 days a month. Some days patients may experience only a mild to moderate background headache, where as on other days a more intense full-blown migraine attack may occur.
Among the reasons for the progression from intermittent to more frequent headaches, medication overuse stands above the rest. This occurs when an abortive medication (pain killer, triptan, some others) is used more than 2-3 days a week, week after week, month after month. Other causes of this progression may include emotional distress, genetic influences, obesity, hypothyroidism, and other factors. At times no apparent reason for the progression occurs.
A complete article on chronic daily headache is included in our new book, Headaches That Persist. The article was authored by a headache neurologist and includes the subcategories of chronic daily headache.
By Dr. Joel Saper, M.D., F.A.C.P., F.A.A.N.
Neurologist - Headache specialty
Michigan Headache & Neurological Institute
Ann Arbor, Michigan