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