What is a migraine headache?
A migraine headache is considered a vascular headache because it is associated with changes in the size of the arteries within and outside of the brain.

Who is affected by migraines?
The National Headache Foundation estimates that nearly 30 million Americans suffer from migraines. Migraines occur about three times more frequently in women than in men. Each migraine can last from four hours to three days. Occasionally, it will last longer.

What causes a migraine?
The exact causes of migraines are unknown, although they are related to changes in the brain as well as to genetic causes. People with migraines may inherit the tendency to be affected by certain migraine triggers, such as fatigue, bright lights, weather changes and others.

For many years, scientists believed that migraines were linked to the expanding (dilation) and constriction (narrowing) of blood vessels on the brain’s surface. However, it is now believed that migraine is caused by inherited abnormalities in certain areas of the brain.

There is a migraine "pain center" or generator in the mid-brain area. A migraine begins when hyperactive nerve cells send out impulses to the blood vessels, causing constriction, followed by the dilation of these vessels and the release of prostaglandins, serotonin and other inflammatory substances that cause the pulsation to be painful.

Certain brain cells that use serotonin as a messenger are involved in controlling mood, attention, sleep, and pain. Therefore, chronic changes in serotonin can lead to anxiety, panic disorder, and depression.

What triggers a migraine?
Many migraines seem to be triggered by external factors. Migraine sufferers can help the physician identify these triggers. Possible triggers include:

• Emotional stress is one of the most common triggers of migraine headache. Migraine sufferers generally are highly affected by stressful events. During stressful events, certain chemicals in the brain are released to combat the situation (know as the "flight or fight" response). The release of these chemicals can provoke vascular changes that can cause migraine. Repressed emotions surrounding stress, such as anxiety, worry, excitement and fatigue can increase muscle tension and dilated blood vessels can intensify the severity of migraine.
• Sensitivity to specific chemicals and preservatives in foods. Certain foods and beverages, such as aged cheese, alcoholic beverages, and food additives such as nitrates (in pepperoni, hot dogs, luncheon meats) and monosodium glutamate (MSG, commonly found in Chinese food) may be responsible for triggering up to 30% of migraines.
• Caffeine. Excessive caffeine consumption or withdrawal from caffeine can cause headaches when the caffeine level abruptly drops. The blood vessels seem to become sensitized to caffeine, and when caffeine is not ingested, a headache may occur. Caffeine itself is often helpful in treating acute migraine attacks.
• Changing weather conditions such as storm fronts, barometric pressure changes, strong winds or changes in altitude
• Menstrual periods
• Tension
• Excessive fatigue
• Missing meals
• Changes in normal sleep pattern

Are migraines hereditary?
Yes, migraines have a tendency to run in families. Four out of 5 migraine sufferers have a family history of migraines. If one parent has a history of migraines, the child has a 50% chance of developing migraines, and if both parents have a history of migraines, the risk jumps to 75%.

What are the symptoms of migraines?
The symptoms of migraine headaches can occur in various combinations and include:

Type of pain
The pain of a migraine can be described as a pounding or throbbing. The headache often begins as a dull ache and develops into throbbing pain. The pain is usually aggravated by physical activity.

Severity/intensity of pain
The pain of a migraine can be described as mild, moderate, or severe.

Location of pain
The pain can shift from one side of the head to the other, or it can affect the front of the head or feel like it’s affecting the whole head.

Duration of pain
Most migraines last about 4 hours, although severe ones can last up to a week.

Frequency of headaches
The frequency of migraines varies widely among individuals. It is common for a migraine sufferer to get 2-4 headaches per month. Some people, however, may get headaches every few days, while others only get a migraine once or twice a year.

• Sensitivity to light, noise and odors
• Nausea and vomiting, stomach upset, abdominal pain
• Loss of appetite
• Sensations of being very warm or cold
• Paleness (pallor)
• Fatigue
• Dizziness
• Blurred vision
• Diarrhea (rare)
• Fever (rare)

Warning signs
Symptoms that signal the onset of a migraine are used to describe two types of migraine dysfunction:

• Migraine with aura (known as "classic" migraine)
• Migraine without aura (known as "common" migraine)

"Aura" is a physiological warning sign that a migraine is about to begin.

What are the symptoms of migraines with aura?
Migraines with auras occur in about 15-20% of migraine sufferers. An aura can occur before, during, or after the pain occurs and last from 15 to 60 minutes. The symptoms always last less than one hour. Visual auras include:

• Bright flashing dots or lights
• Blind spots
• Distorted vision
• Temporary vision loss
• Wavy or jagged lines

There are also auras that can affect the other senses. These auras can be described simply as having a "funny feeling," or the person may not be able to describe the aura. Other auras may include ringing in the ears (tinnitus), or having changes in smell (such as strange odors), taste, or touch.

Rare migraine conditions include these types of neurological auras:

Hemiplegic migraine: temporary paralysis (hemiplegia) or neurological or sensory changes on one side of the body. The onset of the headache may be associated with temporary numbness, dizziness or vision changes.

Retinal migraine: temporary, partial or complete loss of vision in one eye, along with a dull ache behind the eye that may spread to the rest of the head.

Basilar artery migraine: dizziness, confusion or loss of balance can precede the headache. The headache pain may affect the back of the head. These symptoms usually occur suddenly and can be associated with the inability to speak properly, ringing in the ears, and vomiting. This type of migraine is strongly related to hormonal changes and primarily affects young adult women.

Status migrainosus: a rare and severe type of migraine that can last 72 hours or longer. The pain and nausea are so intense that people who have this type of headache often need to be hospitalized. Certain medications, or medication withdrawal, can cause this type migraine syndrome.

Ophthalmoplegic migraine: pain around the eye, including paralysis in the muscles surrounding the eye. This is an emergency medical condition, as the symptoms can also be caused by pressure on the nerves behind the eye or an aneurysm. Other symptoms of ophthalmoplegic migraines include droopy eyelid, double vision, or other vision changes.

What are the symptoms of migraines without aura?
Migraines without auras are more common, occurring in 80 to 85 percent of migraine sufferers. Several hours before the onset of the headache, the person can experience vague symptoms, including:

• Anxiety
• Depression
• Fatigue or tiredness

How are migraines treated?
Many medications are available to treat migraines.

Symptomatic relief: Symptomatic relief medications are used to relieve symptoms associated with headaches, including the pain of a headache or the nausea and vomiting associated with migraine.

Over-the-counter medications are effective for some people with migraines. The main ingredients in pain-relieving medications are ibuprofen, aspirin, acetaminophen, naproxen, and caffeine. Be cautious when taking over-the-counter pain-relieving medications, because sometimes they can contribute to a headache, or their overuse can cause analgesic-rebound headaches or a dependency problem. If you are taking any over-the-counter pain medications more than three times a week or daily, it’s time to see your health care provider, who can suggest prescription medications that may be more effective.

Anti-nauseants are often needed to relieve nausea that accompanies migraines.

Abortive medications are most effective when used at the first sign of a migraine to stop the process that causes the headache pain. By stopping the headache process, abortive medications help prevent the symptoms of migraines including pain, nausea, light-sensitivity, etc. Abortive medications work by constricting the blood vessels, bringing them back to normal and relieving the throbbing pain.

Preventive (prophylactic) medications may be prescribed when the headaches are severe, occur more than two or three times a month and are significantly interfering with normal activities. Preventive medications reduce the frequency and severity of the headaches and are generally taken on a regular, daily basis.

All of these treatments should be used under the direction of a headache specialist or physician familiar with migraine therapy. As with any medication, it is important to carefully follow the label instructions and your physician’s advice.

Biofeedback
Biofeedback training can also help. People can learn to recognize stressful situations that trigger migraines so they can learn to control these situations. If the migraine begins slowly, many people can use biofeedback to stop the attack before it becomes full blown.

How can migraines be prevented?
Identifying and then avoiding migraine triggers should reduce the frequency of your migraine attacks.

Recalling what was eaten prior to an attack may help you identify chemical triggers and make the necessary dietary changes to avoid these triggers in the future.

Women who get migraines during their menstrual periods typically find relief during pregnancy and after menopause. Hormonal treatment of migraines has not been satisfactory, however. Generally, becoming aware of the menstrual cycle patterns as they relate to the onset of the headaches can help you take preventive action against the headaches.

Stress management and coping techniques, along with relaxation training, can help prevent or reduce the severity of the migraine attacks.

Migraine sufferers also seem to have fewer attacks when they eat on a regular schedule and get adequate rest.

Regular exercise - in moderation - can also help prevent migraines.

© Copyright 1995-2005 The Cleveland Clinic Foundation. All rights reserved

This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. For additional written health information, please contact the Health Information Center at the Cleveland Clinic (216) 444-3771 or toll-free (800) 223-2273 extension 43771 or visit www.clevelandclinic.org/health/.

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