Headache and Pain Disorders
Headache and pain disorders group the conditions in which head pain, or the closely related pain syndromes managed in neurology, are the defining clinical problem. They include the common primary headaches that arise without an underlying structural cause, such as migraine and tension-type headache, and secondary headaches that signal another disease, such as the headache of meningitis or encephalitis. Because headache is among the most frequent reasons people seek medical care, this area is central to clinical neurology and public health alike.
Definition
Headache and pain disorders are conditions in which pain referred to the head, face, or upper neck is the principal manifestation, classified by the International Classification of Headache Disorders into primary headaches (the disorder itself) and secondary headaches (attributed to another underlying cause).
Scope
This area orients the reader to the major headache categories and to the diagnostic logic that distinguishes benign primary headaches from secondary headaches that demand urgent investigation. It surveys migraine, tension-type headache, cluster headache, and the headache associated with central nervous system infection (meningitis and encephalitis) as representative topics, and it frames how classification and epidemiology organise the field. It is a reference orientation, not a clinical or treatment protocol.
Sub-topics
Core questions
- How is a primary headache distinguished from a secondary headache that signals serious disease?
- What classification framework organises the more than two hundred recognised headache types?
- Why is headache such a large contributor to global disability?
Key concepts
- Primary versus secondary headache
- International Classification of Headache Disorders (ICHD-3)
- Red-flag features signalling dangerous secondary causes
- Migraine, tension-type, and cluster (trigeminal autonomic) headache
- Headache attributed to central nervous system infection
- Global burden of headache disability
Mechanisms
Primary and secondary headaches differ fundamentally in their origin. In primary headaches the pain arises from dysfunction of pain-modulating and trigeminovascular pathways without a separate structural lesion, whereas in secondary headaches the pain is a symptom of an identifiable disease such as infection, raised intracranial pressure, or vascular injury. The International Classification of Headache Disorders provides the operational criteria that separate these groups and that define each specific disorder by its pattern of attacks, associated features, and (for secondary headaches) the underlying condition to which the headache is attributed.
Clinical relevance
Understanding the structure of headache disorders supports evidence appraisal and recognition of the features that distinguish self-limiting primary headaches from headaches that warrant urgent evaluation. This area describes how the conditions are categorised and studied; it is a reference orientation and not a substitute for individual clinical assessment or treatment decisions.
Epidemiology
Headache disorders are extraordinarily common and collectively rank among the leading causes of years lived with disability worldwide. The Global Burden of Disease analyses identify migraine and tension-type headache as the dominant primary headaches by prevalence, with migraine contributing the larger share of disability despite tension-type headache being more prevalent.
Evidence & guidelines
The International Classification of Headache Disorders, 3rd edition (ICHD-3) is the reference standard that defines and codes headache disorders for both clinical practice and research, and the Global Burden of Disease studies provide the principal population-level evidence on prevalence and disability.
History
Systematic classification of headache was consolidated by the International Headache Society, whose first classification (1988) and subsequent revisions culminating in ICHD-3 (2018) replaced earlier, inconsistent terminologies and made headache research comparable across studies and countries.
Related topics
Seminal works
- ichd3-2018
- stovner-2018
Frequently asked questions
- What is the difference between a primary and a secondary headache?
- A primary headache is the disorder itself, with no separate underlying disease, as in migraine or tension-type headache. A secondary headache is a symptom attributed to another condition, such as infection, bleeding, or raised pressure inside the skull, and may require urgent evaluation.
- Which headache disorders cause the most disability?
- Global Burden of Disease analyses identify migraine and tension-type headache as the most burdensome primary headaches; tension-type headache is more prevalent, but migraine accounts for the greater share of disability.