Migraine is an ailment of the brain that afflicts many sufferers. It causes excruciating headaches and a number of other symptoms such as disturbance of vision; nausea; and sensitivity to noises, smells and lights. About 18% of women and 6% of men suffer from migraine. Attacks can be as frequent as a few times a week or as infrequent as once in a lifetime. Most sufferers experience migraine attacks a few times a month.

Causes

The root cause of migraine is not known. All that can be determined is that something causes an expansion of the blood vessels inside the brain. This leads to the symptoms experienced by sufferers. Migraine attacks often happen when the brain has been under strain and the strain is removed. If a person is worrying about something and then the worry is suddenly removed, the result is often a migraine. This explains why Friday evening is a common time for migraines, as the strain of working during the week is suddenly removed.

Symptoms

Migraine sufferers experience a variety of symptoms. The most common are visual disruption and headaches. Sufferers may not get all the symptoms. Headaches without visual disruption are common but some people get the visual disruption without any headache. A migraine headache without any visual disturbance is known as a 'common migraine'. A headache preceded by the visual disruption is called a 'classic migraine'.

Visual Disruption

The usual symptoms of a migraine attack start with what are known as 'aura'. These usually consist of a disruption to vision. This can be in the form of a blind spot. In the words of one Researcher:

I had real difficulty reading. I had what seemed to be a blank area (like an extended blind spot) immediately to the right of my central vision, which meant that I couldn't see the last couple of characters of a... word I was reading... I went to mention this to my sister but looking at her face from 3m away, if I looked at a spot above her right eye, I couldn't see the left half of her face.

After a few minutes it started to seem essentially like a shimmering/pulsating curved patch in the lower right quarter of my visual field with the real world in that area being obliterated by a combination of shimmering... an overlaid set of flickering and shifting horizontal and vertical black-and-white strips.

Thankfully, this Researcher did not go on to experience the pain of a migraine headache.

Other visual symptoms include a zigzag pattern in the periphery of vision, which may be grey and silvery or brightly coloured. What is surprising about such visual effects is how consistent they are between migraine sufferers. Although the various blobs, zigzags and spots seem random, they can be exactly the same in different people.

In some rare cases, the aura can take other forms such as hallucinations (seeing or hearing things that are not there), numbness in parts of the body, or loss of speech.

Headache

The headache usually starts about 15 - 30 minutes after the visual disturbances. It is often but not always confined to one side of the head; the word 'migraine' itself is a corruption of the Greek term hemikrania meaning a pain in half the head. A migraine headache is extremely intense and can last from four to 72 hours. The sufferer becomes very sensitive to noise and bright lights; any sound or light can increase the pain. Any movement of the head also causes the pain to intensify. Most sufferers hide in a dark room until the headache has gone.

Nausea

Some sufferers also experience nausea and vomiting. They become very sensitive to smells; any sort of a smell can make them nauseous.

Triggers

Most people get migraines for a reason. As mentioned before, the migraine is often caused by the removal of a strain from the brain, but there usually needs to be something else as well to trigger the attack. The most common triggers are foods and visual effects.

Visual Triggers

• High contrast black and white stripes; for example, Venetian blinds against a bright sky.

• Dim light with low contrast; for example trying to read in a badly lit room.

• Very bright light shining into the side of the eye.

• Flashing light at 10 - 60 Hz (for example, a badly adjusted computer screen).

Food Triggers

Many different types of food have been named as possible triggers of migraine. The most common by far is chocolate:

• Chocolate
• Red wine
• Monosodium glutamate (MSG), a taste enhancer used in many processed foods such as crisps¹, dried soups and Chinese food
• Caffeine
• Nitrates and nitrites, food additives often found in sausages, salami, and dried meat products
• Tyramine, found in aged cheeses such as Parmesan

It has been proposed that one of the symptoms of an impending migraine attack is a craving for particular foods and that the craving is caused by the migraine attack rather than the attack being caused by eating the food. This theory is not generally accepted.

Female Hormone Triggers

Almost three times as many women as men suffer from migraine. The reason for this is that in women, migraine can be triggered by the changes in the levels of the female hormones progesterone and oestrogen. These can be caused by puberty, menstruation, contraceptive pills, pregnancy or menopause. The changing hormonal level may prevent migraine attacks as well as triggering them: some women who are regular sufferers find their headaches go away during pregnancy, for example.

Other triggers

Other things that can trigger migraine include:

• Irregular sleep patterns
• Sudden changes in temperature or air pressure
• Extreme hunger

Treatment

There is no known cure for migraine, but the headaches can be treated. It is always best to get advice from a doctor. A headache may be just a headache or it may a symptom of something more serious. Most people are not competent to tell, even if they have read an informative entry like this, so don't think that you are the world's expert on migraine! Consult your doctor.

Your doctor may prescribe medicine for relief from migraine. These generally have two components; one to relieve the swelling in the brain and one to block the pain. Be careful! Some pain killers designed to combat other sorts of head pain, such as beta blockers, work by enlarging the blood vessels in the brain, which will only make a migraine worse.

Rather than combatting the migraine itself, sufferers are advised to find out what triggers the migraine for them. This can be done by keeping a 'headache diary' and by careful observation. Sleep patterns, food eaten and other possible causes should all be noted in the diary each day. Once the trigger has been identified, it can be then be avoided.

The following table suggests method for avoiding migraine, given the particular trigger.