Headache is one of the most common public health concerns worldwide. Its prevalence is high, though the exact figure of prevalence is difficult to methodologically determine. Headache mostly affects people in their productive years, ie, late teens to 50s, and the cost of lost productivity and work hours due to headache is enormous. Headache is also the most common reason for neurologic consultation. Despite such magnitude in pain, disability, and cost, headache is often underdiagnosed and undertreated. One study showed that approximately half of those suffering from migraine had been seen by doctors, and most of them received neither correct diagnosis nor effective treatment (57); this may be because of clinical and sociological barriers as most headaches are episodic, nonfatal, and noncontagious. The condition may, therefore, be perceived as less serious and not a high priority (World Health Organization 2004; 95).
To broaden our views on the disorder, we need reliable information from various epidemiological studies. Epidemiology is a science aiming to examine patterns of disease occurrence in human populations and determinants of these patterns (55). Epidemiological studies tend to address causation and various public health issues. In this article, we will explore population frequency of headache as well as headache risk factors, comorbidities, course, and resultant disability. We will focus more on primary headache due to its higher prevalence and the availability of comprehensive studies. But first, we will address methodological factors to be considered when determining the epidemiology of headache.
| || |
• Primary headaches are a common problem in the general population and 1 of the most common complaints in neurology clinics.
| || |
• Migraine has a prevalence of approximately 12% worldwide and contributes to around 40% to 50% of the overall headache burden.
| || |
• Tension-type headache is the most prevalent primary headache in the population and contributes to 60% of the total headache burden.
| || |
• Chronic daily headache (including 4 subtypes: chronic migraine, chronic tension-type headache, new daily persistent headache, and hemicrania continua) is the most common headache disorder seen in headache clinics; many patients with chronic daily headache overuse abortive headache medications.
| || |
• Psychiatric conditions, especially depression and anxiety, are common comorbidities.