Migraine Headache Causes

What causes migraine headache?

Migraine headaches result from a combination of blood vessel enlargement, abnormal blood vessel contraction, and the release of chemicals from the nerve fibers that wrap around these enlarged blood vessels. During the headache, when an artery enlarges, usually on the outside of the skull, just under the skin of the temple, it causes a release of pro-inflammatory chemicals that can cause pain. The result is further swelling of the artery, which compounds the painful symptoms and prolongs the pain and recovery time from the migraine headache.

A migraine headache causes abnormal changes in the sympathetic nervous system (SNS), which regulates some of the automatic functions of the body such as digestion, blood circulation and sensory perception. Symptoms that the SNS has been affected can include nausea, diarrhea, and vomiting, cold extremities, pupil dilation and perspiration. This disturbance in the SNS also delays digestion and food absorption in the stomach, leads to cold hands and feet, and heightens sensitivity to light, sound, and sometimes smell and touch.

Liver Function and migraine

The liver detoxifies and metabolizes millions of complex substances in the body via liver cells, or hepatocytes. With the introduction of new environmental pollutants, food additives, prescription medications, and the additional stress of the "information age," the liver cells are overworked. As a result, many people are experiencing a decline in liver funtion. Several diseases have been linked to a decline in liver funtion including as rheumatoid arthritis, gout, eczema, migraine headaches and premenstrual syndrome. The connection between the liver and migraine headaches was established when scientists discovered that the vascular changes associated with migraine are linked with altered serotonin metabolism. Since the metabolism of serotonin takes place in the liver, some researchers now believe that by improving liver funtion, the frequency and severity of migraine headaches may be reduced, thereby normalizing serotonin metabolism and restoring vascular health. Milk thistle (Silybum marianum) has a long historical use for normalizing liver funtion, and is widely prescribed by herbalists throughout the US, Canada and Europe for liver protection.

Sleep and migraine

Sleep disturbances, such as not enough sleep, too much sleep, poor quality of sleep, and frequent waking at night are associated with both migraine and tension headaches, whereas improved sleep habits have been shown to reduce the frequency of migraine headaches. Sleep can shorten the duration of migraine headaches and hasten the recovery process.

Skipping meals, late night meals, and migraine

Fasting, or skipping meals, possibly may trigger migraine headaches by causing the release of stress-related hormones and lowering blood sugar, two factors that can negatively affect the vascular system, thereby inducing migraine headache in some individuals. Therefore, migraine sufferers should take care to eat regular meals and avoid skipping meals. Late night meals can also lead to similar, inflammatory vascular changes and should also be avoided.

Bright lights and migraine

Bright lights can cause headaches in healthy and migraine-prone individuals alike, but people who suffer from migraines may have a reduced threshold for light-induced headache pain. Bright sunlight, television, and flashing lights all have been reported to trigger migraine headaches.

Caffeine and migraine

Caffeine can be found in coffee, tea, and over the counter medications. Caffeine in low doses can increase alertness and energy, but caffeine in high doses can cause insomnia, irritability, anxiety, and headaches. The use of caffeine-containing analgesics can cause rebound migraine headaches.

Foods and migraine

Chocolate, fermented foods, aged cheeses, and some fruits such as figs have been indicated in causing migraine headaches, but scientific studies have not consistently demonstrated an association between food consumption and headaches. Red wine has been shown to cause migraine headaches in some migraine sufferers, but it is not clear whether white wine also will cause migraine headaches. MSG, a naturally-occurring or added flavor enhancer can trigger migraines for some people. All of these foods stimulate neurotransmitters that are overly active during migraine. Medications that relieve migraine headache pain act on the same receptors as the foods listed above, but in a favorable way.

Female hormones and migraine

Women who suffer from migraines are more likely to experience migraines around the time of their periods, usually starting about 2 days before the period starts, and subsiding after 1 to 3 days. Often times it is the most severe migraine that a woman will experience monthly. Other women experience migraine headaches only during the menstrual period. The term "menstrual migraine" is used mainly to describe migraines that occur in women who have most migraine headaches 1-2 days before the onset of the period. Estrogen and progesterone levels decline prior to menstruation; this is thought to be the mechanism for triggering “menstrual migraines,” as a decline in these hormones leads to vascular changes that can induce migraine headaches.

Many people who experience migraines can clearly identify triggers, or environmental factors that initiate the onset of migraine symptoms, while others cannot. Potential migraine triggers can include:

• Allergies and allergic reactions
• Bright lights, loud noises
• Overexposure to sunlight and heat
• Certain odors or perfumes
• Physical or emotional stress
• Excessive exercise
• Changes in sleep patterns or irregular sleep
• Smoking or exposure to smoke
• Skipping meals or fasting
• Alcohol consumption, especially red wine
• Menstrual cycle fluctuations, birth control pills, hormone fluctuations during menopause onset
• Tension headaches
• Foods containing tyramine (red wine, aged cheese, smoked fish, chicken livers, figs, and some beans), monosodium glutamate (MSG), or nitrates (like bacon, hot dogs, and salami) Other foods such as chocolate, nuts, peanut butter, avocado, banana, citrus, onions, dairy products, and fermented or pickled foods

For some women, the decline in the blood level of estrogen that starts about 2 days before the onset of menstruation, is a trigger for migraine headaches (sometimes referred to as menstrual migraines).

Exposure to a “trigger” doesn’t always induce a migraine, and avoiding triggers does not always prevent migraines. The current level of stress as well as hormonal changes can influence one’s susceptibility to known or suspected environmental triggers for migraine headache.

Jay W Marks, MD. 2009. Migraine headache. (Online) http://www.medicinenet.com/migraine_headache/page5.htm#toco accessed 02.23.2010

Dowson AJ, Lipscombe S, Sender J, Rees T, Watson D. New Guidelines for the Management of Migraine in Primary Care. Curr Med Res Opin. 2002;18(7):414-439. accessed 02.23.2010

Goetz CG, Pappert EJ. Textbook of Clinical Neurology. 2nd ed. Philadelphia, PA: Saunders; 2003. accessed 02.23.2010

Holroyd KA, Drew JB. Behavioral approaches to the treatment of migraine. Semin Neurol. 2006 Apr;26(2):199-207. accessed 02.23.2010