In medicine a headache
is a symptom
of a number of different conditions of the
. Some of the causes are benign while
others are medical emergencies.
There are a number of different classification systems for
headaches. The most well-recognized is that of the International Headache
Treatment of a headache depends on the underlying etiology or
cause, but commonly involves analgesics
The first recorded classification system that resembles the modern
ones was published by Thomas Willis
in De Cephalagia
in 1672. In 1787 Christian Baur
generally divided headaches
(primary headaches) and
(secondary ones), and
defined 84 categories.
Today headaches are most thoroughly classified by the International Headache
's International Classification of Headache Disorders
(ICHD), which published the second edition in 2004. This
classification is accepted by the WHO
Other classification systems exist. One of the first published
attempts was in 1951. The National Institutes of Health developed a classification system in
Headaches can also be classified by severity and acuity of onset.
Headaches that are both severe and acute are known as thunderclap headaches
Classification of Headache Disorders
(ICHD) is an in-depth
classification of headaches
published by the International Headache
. It contains explicit (operational) diagnostic criteria
disorders. The first version of the classification, ICHD-1, was
published in 1988. The current revision, ICHD-2, was published in
The classification uses numeric codes. The top, one-digit
diagnostic level includes 14 headache groups. The first four of
these are classified as primary headaches, groups 5-12 as secondary
headaches, cranial neuralgia
, central and primary facial pain and
other headaches for the last two groups.
The NIH classification consists of brief definitions of a limited
number of headaches.
Symptoms and signs
Headache associated with specific symptoms may warrant urgent
medical attention, particularly sudden, severe headache or sudden
headache associated with a stiff
; headaches associated with fever
or accompanied by confusion
or loss of consciousness
headaches following a blow to the head, or associated with pain in
the eye or ear; persistent headache in a person with no previous
history of headaches; and recurring headache in children.
in itself is not sensitive to
, because it lacks nociceptors
. However, several areas of the
nociceptors, and can thus sense pain. These include the
extracranial arteries, large veins, cranial and spinal nerves, head
and neck muscles and the meninges
In 2008, the American College of
updated their guidelines on the evaluation
and management of adult patients who have a nontraumatic headache
of acute onset.
While, statistically, headaches are most likely to be primary
(harmless and self-limiting), some specific secondary headache
syndromes may demand specific treatment or may be warning signals
of more serious disorders. Differentiating between primary and
secondary headaches can be difficult.
As it is often difficult for patients to recall the precise details
regarding each headache, it is often useful for the sufferer to
fill-out a "headache diary" detailing the characteristics of the
When the headache does not clearly fit into one of the recognized
primary headache syndromes or when atypical symptoms or signs are
present then further investigations are justified. Neuroimaging
(noncontrast head CT) is recommended if there are new neurological
problems such as decreased level of consciousness, one sided
weakness, pupil size difference, etc or if the pain is of sudden
onset and severe, or if the person is known HIV positive. People
over the age of 50 years may also warrant a CT scan.
Not all headaches require medical attention, and most respond with
(painkillers) such as
or members of
(such as aspirin
A small 2009 study found that 100% oxygen at 15 l / min was
effective at relieving undifferentiated headache pain in the
In recurrent unexplained headaches keeping a "headache diary
" with entries on type of headache, associated
symptoms, precipitating and aggravating factors may be helpful.
This may reveal specific patterns, such as an association with
or with certain foods.It was
reported in March 2007 by two separate teams of researchers that
stimulating the brain with implanted electrodes appears to help
ease the pain of cluster headaches.
has been found to be
beneficial in chronic headaches of both tension type and migraine
type. Whether or not there is a difference between true acupuncture
and sham acupuncture however is yet to be determined.
During a given year, 90% of people suffer with headaches. Of the
ones who are seen in the ER
about 1% have a serious underlying problem.