Except perhaps for head colds, headaches are probably the most common human ailment. Three out of four Americans had a headache during the past year, according to the National Headache Foundation. Usually, headaches are merely passing annoyances that go away with aspirin or after a nap, but as many as 45 million people suffer from chronic and/or severe headaches that seriously interfere with their lives.
All told, headaches account for 80 million of all doctors' office visits and more than 400 million dollars spent on over-the-counter pain relievers each year. Like colds, headaches are not completely understood by scientists. There appears to be various types of headaches, but any hard and fast classification is open to debate, in part, because the types often overlap - both in symptoms and in response to medication. Moreover, triggering factors and modes of relief vary from person to person. Still, the great majority of primary headaches (those not due to underlying diseases) falls into three categories, according to the International Headache Society: tension, migraine and cluster.
Also called a muscle-contraction or stress headache. This is the type of headache that everyone gets occasionally. The dull, steady pain - mild compared to migraine or cluster headaches - may be felt in the forehead, temples, back of neck or throughout the head. A feeling of tightness around the scalp is typical and muscles in the back of the upper neck may feel knotted and tender to the touch. It's not known whether the sustained muscle tension itself or the subsequent restricted blood flow causes the pain.
Tension headaches are associated with stress (often the pain comes after the stress has ended), fatigue or too much/too little sleep. Assuming a posture that tenses your neck and head muscles for long periods of time, such as holding your chin down while reading, can trigger these headaches; as can gum chewing, grinding your teeth or tensing head and neck muscles during sexual intercourse. Men and women are about equally likely to suffer tension headaches.
Tension headaches that occur daily may be a sign of clinical depression. In some cases, the headaches may cause the depression; in others, treating the depression makes the headaches go away.
The word migraine, derived from the Greek, means "half a skull," an apt introduction of the pain which usually occurs in only one side of the head.
Migraines appear to involve the abnormal expansion and contraction of blood vessels in and around the brain.
In some people, migraines start with distorted vision, called an "aura," generally characterized by zigzag patterns of shooting lights, blind spots, and/or a temporary loss of peripheral vision. The throbbing, pulsating pain can be incapacitating and can last anywhere from a few minutes to several days. If longer, it's probably not a migraine. Migraine sufferers may also experience nausea, vomiting and sensitivity to both light and noise.
About 80 percent of all migraine sufferers have a family history of the ailment and women are nearly four times more likely to be afflicted. The typical sufferer is young (under the age of 35) and had her first attack during her teens or twenties. With age, attacks usually become less severe and less frequent. Hormonal changes can play a role; thus susceptible women may have more attacks if they take oral contraceptives or around the time of menstruation. They may have fewer attacks during pregnancy and after menopause. Attacks can also be instigated by certain substances in food, emotional factors and environmental factors, such as glaring light, strong odors and changes in the weather.
Migraines are often accompanied by nausea and vomiting, and frequently affect only one side of the head. In the classic form, the pain follows certain warning signs (the aura), such as flashing lights, blind spots, tingling or numbness on one side of the body. The aura is always the same for each individual. An "abortive" migraine features the aura without the headache. biofeedback and other nontraditional techniques occasionally help prevent, though do not relieve, migraines; heat and other muscle-relaxing steps generally do not do either.
Since migraines may be sparked by specific factors, sufferers should keep a headache diary to pinpoint any possible triggers. People have blamed migraines on alcohol, monosodium glutamate (MSG), nitrites, and a host of other food and drinks. birth control pills, estrogen replacement therapy, menstruation, irregular eating, sleeping schedules, bright lights and noises have also been linked to migraines. The supposed migraine personality: compulsive, neat and rigid is probably a myth.
These strike in a group or "cluster" for up to a few hours and recur daily for days, weeks or months on end. There may be months of freedom between attacks. Some researchers consider cluster headaches a variant of migraines, largely because the excruciating pain is centered on one side of the head, as in a migraine, but unlike the throbbing of a migraine, this pain is steady and piercing. There are other notable differences; typically cluster headaches strike at night or early morning and the pain is located around or behind one eye or in one temple.
Cluster headaches are about six to nine times more likely to strike men than women. The first attack usually appears in a person's 20s or 30s. They are sometimes misdiagnosed as a sinus disorder (because stuffy nose or sinus congestion is a common symptom) or as an abscessed tooth. There's no clear cause, though heavy smoking and drinking are possible contributing or triggering factors.