Migraines and headaches

Migraines are painful headaches often accompanied by nausea, vomiting and sensitivity to light.

Who gets migraines?
Migraines are common. Each migraine can last from four hours to three days. Occasionally, it will last longer.

What causes migraines?
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 expanding and constricting blood vessels on the brain's surface. However, it is now believed that migraines are caused by inherited abnormalities in certain areas of the brain.

There is a migraine "pain centre" or generator in the brain. A migraine begins when hyperactive nerve cells send out impulses to the blood vessels, causing them to clamp down or constrict, followed by dilation (expanding) and the release of prostaglandins, serotonin and other inflammatory substances that cause the pulsation to be painful.

What triggers a migraine?

Many migraines seem to be triggered by external factors. Possible triggers include:
• Emotional stress. This is one of the most common triggers of migraine headache. Migraine sufferers are generally highly affected by stressful events. During stressful events, certain chemicals in the brain are released to combat the situation (known as the "flight or fight" response). The release of these chemicals can provoke vascular changes that can cause a 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 the migraine.
• Sensitivity to specific chemicals and preservatives in foods. Certain foods and drinks, such as aged cheese, alcoholic beverages and food additives such as nitrates (in pepperoni, frankfurter sausages, 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 sensitised 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. Storm fronts, changes in barometric pressure, strong winds or changes in altitude can all trigger a migraine.
• Menstrual periods
• Excessive fatigue
• Skipping meals
• Changes in normal sleep patterns

Migraines and associated conditions

There are some medical conditions that are more commonly associated with migraines, including:
• Asthma
• Chronic fatigue syndrome
• Hypertension
• Raynaud's phenomenon (occurs when blood vessels narrow causing pain and discolouration usually in the fingers)
• Stroke
• Sleep disorders