headache
headache is arguably the commonest of the human ills, and perhaps, in proportion to its impact, one of the least well understood.
There are many different types of headache, whether considered as to how they behave or as to how they are caused. Headache may broadly be classified as primary or secondary: there are situations in which headache itself is the problem (primary headache), and others in which headache is a symptom of some other condition (secondary headache). Headache has been classified in detail by the International Headache Society, and whole textbooks have been written about it.
The main types of primary and secondary headache are listed in the table, which is based on a population survey. The main primary headaches are migraine (which is considered separately under that heading) and ‘tension-type headache — which is the commonest of all. It is often dull, both-sided, mild but otherwise featureless. It is surprisingly poorly understood. One of the most severe forms of headache, and one of the most difficult to treat, is ‘chronic daily headache’, which involves having headache most days of the week for most of the day. This may be either a form of chronic migraine or of tension-type headache; it is probably experienced in some form by up to 4% of the population, and is often associated with analgesic (painkiller) overuse. The daily headache syndrome is often due in part to the constant cycle of taking painkillers and then having their effects wear off: so-called rebound headache. Regular use of painkillers, particularly those containing more than one ingredient, such as mixtures with codeine, caffeine, or barbiturates, is a potent cause of difficulty in the treatment of headache. Also any regular intake of anti-migraine drugs, including ergotamine and triptans (sumatriptan and related compounds), may potentially cause or aggravate this problem.
Headache does not have any single cause. Just as there are many types of headache, there are many causes of the problem. With respect to the cause of the pain the mechanisms are much less well understood for the primary than for the secondary headaches. Whereas the pain due to injury to the skin, for example, is well understood as being due to stimulation of specific nerve endings in conjunction with local inflammatory events, it is not clear in primary head pain whether the nerves are firing normally or abnormally in response to various stimuli. Much work is to be to done, especially in regard to understanding tension-type headache.
Headache due to serious disease is rare, but a sufferer should be concerned about a headache when it has certain features. These include: sudden onset or sudden worsening, such as a severe headache never previously experienced; headache associated with fever, together with neck stiffness or altered consciousness, such as drowsiness; headache that is gradually worsening over a short period — say one to two months; or headache associated with pain in the temples, and pain on chewing, particularly if there is any visual disturbance. These latter symptoms are very important and a sufferer should seek immediate medical attention.
Most countries have established flourishing patient groups, which can be contacted by reference to telephone directories, such as the Migraine Trust in the UK and the American Council for Headache Education in the US.
See also migraine.
There are many different types of headache, whether considered as to how they behave or as to how they are caused. Headache may broadly be classified as primary or secondary: there are situations in which headache itself is the problem (primary headache), and others in which headache is a symptom of some other condition (secondary headache). Headache has been classified in detail by the International Headache Society, and whole textbooks have been written about it.
The main types of primary and secondary headache are listed in the table, which is based on a population survey. The main primary headaches are migraine (which is considered separately under that heading) and ‘tension-type headache — which is the commonest of all. It is often dull, both-sided, mild but otherwise featureless. It is surprisingly poorly understood. One of the most severe forms of headache, and one of the most difficult to treat, is ‘chronic daily headache’, which involves having headache most days of the week for most of the day. This may be either a form of chronic migraine or of tension-type headache; it is probably experienced in some form by up to 4% of the population, and is often associated with analgesic (painkiller) overuse. The daily headache syndrome is often due in part to the constant cycle of taking painkillers and then having their effects wear off: so-called rebound headache. Regular use of painkillers, particularly those containing more than one ingredient, such as mixtures with codeine, caffeine, or barbiturates, is a potent cause of difficulty in the treatment of headache. Also any regular intake of anti-migraine drugs, including ergotamine and triptans (sumatriptan and related compounds), may potentially cause or aggravate this problem.
Headache does not have any single cause. Just as there are many types of headache, there are many causes of the problem. With respect to the cause of the pain the mechanisms are much less well understood for the primary than for the secondary headaches. Whereas the pain due to injury to the skin, for example, is well understood as being due to stimulation of specific nerve endings in conjunction with local inflammatory events, it is not clear in primary head pain whether the nerves are firing normally or abnormally in response to various stimuli. Much work is to be to done, especially in regard to understanding tension-type headache.
Headache due to serious disease is rare, but a sufferer should be concerned about a headache when it has certain features. These include: sudden onset or sudden worsening, such as a severe headache never previously experienced; headache associated with fever, together with neck stiffness or altered consciousness, such as drowsiness; headache that is gradually worsening over a short period — say one to two months; or headache associated with pain in the temples, and pain on chewing, particularly if there is any visual disturbance. These latter symptoms are very important and a sufferer should seek immediate medical attention.
Most countries have established flourishing patient groups, which can be contacted by reference to telephone directories, such as the Migraine Trust in the UK and the American Council for Headache Education in the US.
Primary headache | Secondary headache | ||
|---|---|---|---|
Type | Prevalence (% of all | Cause | Prevalence (% of all |
primary headaches) | secondary headaches) | ||
Types of headache. After Rassmussen, B. K. (1995) Epidemology of headache. Cephalalgia;15:45–68. | |||
tension-type | 69 | systemic infection | 63 |
migraine | 16 | head injury | 4 |
idiopathic stabbing | 2 | vascular disorders | 1 |
exertional | 1 | sub-arachnoid haemorrhage | <1 |
cluster | 0.6 | brain tumour | 0.1 |
Peter J. Goadsby
See also migraine.
Bibliography
Goadsby, P. J. and Silberstein, S. D. (ed.) (1997). Headache. Butterworth–Heinemann, New York. ( Asbury, A. and Marsden. C. D. (ed.) Blue books in practical neurology, Vol. 17.)
Lance, J. W. and and Goadsby, P. J. (1998). Mechanism and management of headache, (6th edn). Butterworth–Heinemann, London.
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