A headache (medically known as cephalalgia) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. It ranks amongst the most common local pain complaints.
Headaches have a wide variety of causes, ranging from eye strain, sinusitis and tension to life-threatening conditions such as encephalitis, meningitis, cerebral aneurysms and brain tumors. When the headache occurs in conjunction with a head injury the cause is usually quite evident; however, many causes are more unclear. The most common type of headache is a tension headache. Some experience headaches when dehydrated; caffeine withdrawal is another common cause.
Treatment of uncomplicated headache is usually symptomatic with over-the-counter painkillers such as aspirin, paracetamol (acetaminophen) or ibuprofen, although some specific forms of headaches (e.g. migraine) may demand other, more suitable treatment.
The brain itself is not sensitive to pain, because it lacks pain-sensitive nerve fibers. Several areas of the head can hurt, including a network of nerves which extends over the scalp and certain nerves in the face, mouth, and throat. The meninges and the blood vessels do have pain perception. Headache often results from traction to or irritation of the meninges and blood vessels. The muscles of the head may similarly be sensitive to pain.
There are four types of headache: vascular, myogenic (muscle tension), traction, and inflammatory.
- The most common type of vascular headache is migraine. Migraine headaches are usually characterized by severe pain on one or both sides of the head, an upset stomach, and, at times, disturbed vision. It is more common in women. After migraine, the most common type of vascular headache is the "toxic" headache produced by fever.
- Other kinds of vascular headaches include cluster headaches, which cause repeated episodes of intense pain, and headaches resulting from high blood pressure (rare).
- Muscular/myogenic headaches appear to involve the tightening or tensing of facial and neck muscles; they may radiate to the forehead. Tension headache is the most common form of myogenic headache.
- Traction and inflammatory headaches are symptoms of other disorders, ranging from stroke to sinus infection.
Specific types of headaches include:
- Medication overuse headaches
- Ictal headache
- Ice cream headache
- Thunderclap headache
- Vascular headache
- Toxic headache
- Coital cephalgia (also known as: sex headache)
- Sinus headache
- Hemicrania Continua
Like other types of pain, headaches can serve as warning signals of more serious disorders. This is particularly true for headaches caused by inflammation, including those related to meningitis as well as those resulting from diseases of the sinuses, spine, neck, ears and teeth.
While statistically headaches are most likely to be harmless and self-limiting, some specific headache syndromes may demand specific treatment or may be warning signals of more serious disorders. Some headache subtypes are characterized by a specific pattern of symptoms, and no further testing may be necessary, while others may prompt further diagnostic tests.
Headache associated with specific symptoms may warrant urgent medical attention, particularly sudden, severe headache or sudden headache associated with a stiff neck; headaches associated with fever, convulsions, 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.
Computed tomography (CT/CAT) scans of the brain or sinuses are commonly performed, or magnetic resonance imaging (MRI) in specific settings. Blood tests may help narrow down the differential diagnosis, but are rarely confirmatory of specific headache forms.
Not all headaches require medical attention, and respond with simple analgesia (painkillers) such as paracetamol/acetaminophen or members of the NSAID class (such as aspirin/acetylsalicylic acid or ibuprofen).
In recurrent unexplained headaches, healthcare professionals may recommend keeping a "headache diary" with entries on type of headache, associated symptoms, precipitating and aggravating factors. This may reveal specific patterns, such as an association with medication, menstruation and absenteeism.
Some forms of headache may be amenable to preventative treatment, such as migraine. On the whole, long-term use of painkillers is discouraged as this may lead to "rebound headaches" on withdrawal. Caffeine, a vasoconstrictor, is sometimes prescribed or recommended, as a remedy or supplement to pain killers in the case of extreme migraine. This has led to the development of Tylenol Ultra, a paracetamol/caffeine analgesic.
Glossary of Migraine
- abdominal migraine __ a type of migraine that mostly affects young children and involves moderate to severe abdominal pain, with little or no headache.
- arteriovenous malformation __ a tangle of veins and arteries that can disrupt the normal flow of blood and are frequently associated with episodic headache. A catastrophic stroke may occur when an arteriovenous malformation in the skull bursts and bleeds into surrounding brain tissue.
- aura __ a warning of a migraine headache. Usually visual, it may appear as flashing lights, zigzag lines, or a temporary loss of vision, along with numbness or trouble speaking.
- autonomic __ occurring involuntary. The autonomic nervous system has many functions, including control of pupil size, eyelid droop, heart rate, breathing rate, digestion, perspiration, and elimination of body waste. Autonomic dysfunction is frequently associated with various types of migraine.
- basilar-type migraine __ a type of migraine, occurring primarily in young women, causing symptoms of abnormal brain stem functioning such as double vision, loss of peripheral vision, numbness, imbalance, or loss of consciousness.
- benign intracranial hypertension __ increased pressure within the brain that causes severe headaches. It can be caused by being overweight, clotting in the major cerebral veins or from certain medications (including some antibiotics, human growth hormone replacement, and vitamin A and related compounds).
- cephalgia __ head pain.
- cervicogenic headache __ a type of headache caused by structural irregularities in either the neck or head.
- chronic headache __ headache that occurs 15 or more days a month over a 3-month period.
- cluster headache __ sudden, extremely painful headaches that occur in a closely grouped pattern several times a day and at the same times over a period of weeks.
- computed tomography (CT) __ a type of diagnostic imaging that uses X-rays and computer technology to produce two-dimensional images of organs, bones, and tissues.
- cortical spreading depression __ a wave of increased brain activity that slowly spreads from the back toward the front of the brain’s surface and may be the basis for migraine aura.
- electroencephalogram (EEG) __ a test to record electrical brain waves.
- episodic __ comes and goes.
- ergot derivative drugs __ drugs that bind to the neurotransmitter receptor for serotonin and help to decrease the transmission of pain messages along nerve fibers.
- hemicrania continua __ one-sided headaches that are chronic or continuous and respond to indomethacin treatment.
- hemiplegic migraine __ a type of migraine causing temporary paralysis on one side of the body.
- hypnic headache __ a rare form of headache that awakens individuals at night (also called “alarm-clock headache”).
- ice cream headache __ a painful headache brought on by changes in blood flow that result from a sudden chilling of the roof of the mouth.
- ischemic stroke __ stroke caused by a clot that blocks blood flow to the brain.
- low CSF pressure headache __ a headache due to a leak of cerebrospinal fluid (CSF) following removal of a small sample of the fluid for testing, or caused by an internal spinal fluid leak .
- magnetic resonance imaging (MRI) __ a diagnostic imaging test that uses magnetic fields, radio waves, and computer technology to produce detailed images of body structures.
- medication overuse headache __ caused by the overuse of drugs (more than 3 times weekly) to treat headache. While the medication may help to relieve the headaches temporarily, over time the underlying headache becomes worse and occurs more frequently, creating a vicious cycle of medication use and head pain. The pain improves when the medication is stopped.
- meninges __ the three layers of membrane that cover the brain and spinal cord.
- menstrually-related migraine __ a migraine that affects women around the time of their period.
- migraine __ headaches that are usually pulsing or throbbing and occur on one or both sides of the head. They are moderate to severe in intensity, associated with nausea, vomiting, sensitivity to light and noise, and worsen with routine physical activity.
- new daily persistent headache __ a type of treatment-resistant chronic headache marked by daily pain that can last for years.
- nociceptors __ nerve fiber endings that receive and transmit pain signals.
- paroxysmal hemicrania __ a rare form of headache that usually begins in adulthood and is marked by one-sided attacks that typically occur 5 to 40 times a day.
- postdrome __ the period following the headache.
- premonitory __ meaning before. Some individuals with migraine experience premonitory symptoms up to 24 hours prior to headache pain.
- primary exertional headache __ headache brought on by fits of coughing or sneezing, or by intense physical activity such as running or lifting.
- primary headaches __ headaches that occurs on their own with no detectable underlying cause, such as migraine, tension-type headache, and the trigeminal autonomic cephalgias.
- primary stabbing headache __ also called “ice pick headache” or “jabs and jolts” headache for its extremely intense pain that develops suddenly and generally lasts 1 to 10 seconds.
- retinal migraine __ a type of migraine that is characterized by attacks of visual loss or disturbances in one eye.
- reversible cerebral vasoconstriction syndrome __ a narrowing of the arteries in the brain that can be accompanied by sudden, “thunderclap” headache. It can occur during pregnancy and with the use of vasoactive drugs.
- secondary headaches __ headaches that are caused by an underlying condition or disease.
- serotonin __ a neurotransmitter present throughout the body and brain that plays an important role in headache and migraine, mood disorders, regulating body temperature, sleep, vomiting, sexuality, and appetite.
- status migrainosus __ migraine lasting more than 72 hours.
- SUNCT (Short-lasting, Unilateral, Neuralgiform headache attacks with Conjunctival injection and Tearing) __ a rare form of headache marked by brief recurrent bursts of moderate to severe burning, stabbing, or throbbing pain, usually on one side of the head and around the eye or temple, accompanied by symptoms including watery, reddish eyes, and runny nose.
- tension-type headache __ a primary headache that is band-like or squeezing and does not worsen with routine activity. It may be brought on by stress.
- trigeminal neuralgia __ a chronic pain condition that causes extreme, sporadic, sudden burning or shock-like face pain that lasts anywhere from a few seconds to as long as two minutes per episode.
- trigger __ something that brings about a disease or condition.
- triptans __ a family of drugs used to treat migraines and cluster headaches by preventing or stopping nerve tissue inflammation and resulting changes in blood vessels.
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