Migraine Fact Sheets
This fact sheet outlines the main aspects of trigger factors in relation to people with migraine.
What is migraine?
Migraine is a complex condition with a wide variety of symptoms. For many people, of course, the main feature is a painful headache. For others, the symptoms include disturbed vision, sensitivity to light, sound and smells, feeling sick and vomiting. Migraines may result in your having to lie still for several hours. The symptoms will vary from person to person and those who suffer from migraine may experience differing symptoms during different attacks. The attacks may also vary in length and frequency. People are completely free from migraine symptoms between attacks.
What is a trigger?
A trigger is any event, change, external stimulus or physical act which seems to result in migraine. It precedes the attack by a short interval which could be as much as up to 6 to 8 hours. Identifying a trigger is not always easy. Almost any factor can trigger an attack in a person predisposed to this condition and the list of possible suspects can be long and confusing.
What triggers your migraine?
People with migraine often avoid cheese, chocolate, citrus fruits and red wine. For most people, however, just avoiding certain foods will not prevent their migraines occurring as the situation is more complicated than that. Trigger factors seem to build up over a period of time and together result in a migraine attack. This helps to explain why, if you have a tendency to migraine, you might eat a certain food on one day and have no ill effects whereas on another day you will experience a migraine.
Trigger factors are certainly present at the onset of migraine attacks, but it is not possible to state simply that chocolate or cheese, for example, “causes” migraines. These are factors which can have a part to play, if you are predisposed to migraine.
Dr Anne MacGregor (Understanding Migraine and Other Headaches) gives an excellent explanation of this process:
‘Imagine a migraine ‘threshold’ that is determined by your genetic makeup. This threshold is also raised or lowered by external factors, as well as internal changes in your brain. Varying triggers occur over a period of time. If a sufficient number of different internal and environmental triggers build up to cross the current threshold a migraine attack is initiated. This explains why you do not always get a migraine attack in similar situations – perhaps your threshold fluctuates or the number or importance of triggers varies. Consequently, missing a meal and less obvious triggers such as flickering sunlight or a lack of sleep do not always bring on an attack. However, if any or all of these are combined with a period of stress at work or hormone changes an attack may occur.’
You may feel full of energy before an attack and rush around. When the attack begins you may think your migraine was therefore caused by this over activity. In fact such mood changes (which may equally be experienced as a low mood), cravings for sweet things, tiredness, incessant yawning, increased energy or feeling thirsty can all be a sign that the attack has already begun (called the premonitory phase).
It is important to remember that your trigger factors are likely to change over time and new triggers may be discovered if your circumstances change. Stress and red wine may be implicated at times whereas neck and back problems at other times may be more significant.
A migraine diary
It has been suggested that rather than trying to decide what individual factor triggers a migraine, it is more useful to discover how many triggers are needed to start the migraine. This is where keeping a trigger diary can be so helpful.
The diary can include information on as many aspects of daily life as possible to see what may be a trigger, including:
- what and when you eat
- missed or delayed meals
- your medication
- social and work activities
- your bowel movements
- vitamins or any health products taken
- the exercise you take
- how much sleep you have
- other aspects such as environmental factors
- women should record details of their menstrual cycle.
Then the diary can record the physical aspects of the attack such as:
- when the head pains started
- if there are other symptoms (such as being sick or having vision problems)
- how long the attacks last and
- where the pain is
It is vital that you record the number of attacks you have in a month. It is often useful noting if you did anything different prior to the attack such as missing a meal. The 6-8 hours before the migraine attack are particularly important to record. The diary may then highlight a particular trigger or series of triggers which could be avoided or minimised.
Start recording your migraine attacks now with an online migraine diary or read our Migraine Diaries fact sheet.
How to keep a trigger diary
It may be helpful to look at your daily list of potential triggers before you go to bed each night even when you have not had a migraine. The trigger diary should then be reviewed after you have experienced at least three migraines. The information should be compared to see if there is a build up of factors which coincide with the attacks.
So, for example, if you experience your migraines in the late mornings, it may be that low blood sugar due to lack of food is implicated. Eating a snack in the mid morning may be a simple remedy to help alleviate this.
You should then divide your list of triggers into two columns:
- those which you can do something about (such as avoiding missing meals or sleeping late at weekends)
- those which are beyond your control (such as your menstrual cycle or starting a new job)
You may then be able to cut out those triggers which you can influence one at a time and record any changes in the pattern of your migraine.
Many people with migraines are advised to avoid particular foods, however, they may find that they can control their migraine by identifying other trigger factors with only limited changes to their diet. Some of the more common migraine triggers are listed below.
If, however, you think a certain food item does trigger your migraine, first try to establish whether this is the case using a trigger diary. If you are concerned about avoiding any food related trigger factors you can see your GP, practice nurse or ask for a referral to a dietician for specialist advice.
Changes in routine
Some people find that changes in their routine can contribute to a migraine. For example changing sleep patterns or changes caused by long journeys can precede an attack. Even pleasant changes such as a holiday can be implicated.
Many people complain that they suffer migraines at the weekend. At the weekend you may have a change in many of your daily routines such as eating times, reduced caffeine consumption which is particularly noticeable if you have a ‘lie in’ after a busy week. See also stress, sleep, and caffeine below.
Migraines and stress are strongly linked. Indeed, anxiety, excitement and any form of tension and shock may all lead to a migraine attack. However, some people report that their migraines start when the stress reduces. This is sometimes experienced as “weekend headaches” when, after a busy and stressful week at work, an individual might experience a migraine at the weekend when they are more relaxed.
The complex nature of trigger factors is illustrated by sleep. Both too much and too little sleep can be implicated in a migraine starting. Some people find that sleepless nights, a number of late nights and being over tired can trigger a migraine. Other people find that sleeping in or dozing in the mornings has the same effect.
Excessive consumption of caffeine may contribute to the onset of a migraine attack. You could try not having more than 4 or 5 cups of tea, coffee or cola in a day. Some people find that suddenly stopping caffeine altogether can also be a trigger factor. If you suspect this, you may wish to cut down on caffeine more gradually. Some people find that consuming less caffeine at the weekend can have an impact on migraine attacks, but you should also note that caffeine can be found in many products including chocolate and over the counter painkillers.
Hormonal changes in women
Migraine is closely associated with female hormones. Some women find their migraines start at puberty, and are linked to their menstrual cycle. The additional hormonal trigger for women may explain why more women than men experience migraine during their reproductive years. The menopause is often the most difficult time for women with migraine.
There are certain trigger factors which can be related to environmental issues such as high altitude, weather changes, high humidity, loud noises, exposure to glare or flickering lights.
Sitting in front of a computer at home or work for long periods of time can cause problems if you experience migraine. Following common sense precautions such as taking regular breaks, using anti glare screens and good lighting can help prevent this sort of difficulty.
Sitting comfortably is very important when you use a computer to avoid muscle tension building up in the head, neck and shoulders. This muscle tension is implicated in the onset of migraine.
Food related triggers occur in about 10% of people with migraine. Many people will crave sweet food such as chocolate before the pain of the migraine is experienced which leads them to conclude that eating sweet food is a cause. However, sometimes the craving for particular food is a symptom of the beginning of the migraine.
Lack of food
Missing meals or eating sugary snacks instead of a balanced meal can all contribute to a migraine attack. Insufficient food is probably one of the most important dietary triggers. You may find that eating small nutritious snacks at regular intervals can help to control your attacks.
Some food products contain chemicals or additives which may also be implicated in an attack. Ones which are frequently mentioned by people with migraine are monosodium glutamate, nitrates and aspartame.
Alcohol and cheese
There is some evidence that red wine may trigger a migraine because it contains tyramine which has been linked to migraines. Certainly many people with migraine avoid red wine. Tyramine is also found in other food products such as soft cheeses like camembert and brie.
Mild dehydration can have an impact on people who have migraine. It is recommended that you should drink at least 8 glasses of water per day. This is in addition to any other drinks you may have. Fizzy drinks can contain the sweetener aspartame which some people link to their migraines.
Taking cocaine and withdrawal from cocaine can trigger an attack.
Like sleep, exercise can both help to prevent migraines and conversely can be a trigger factor. Regular exercise which is built up gently can help to prevent migraine. It also stimulates the body to release its own natural painkillers, as well as increasing the individual’s sense of well-being and general health. Sudden vigorous exercise, particularly for people who do not usually take exercise, can be a trigger factor.
The use of contraceptives which contain hormones such as the contraceptive pill can trigger migraine for some women. Medical advice should always be sought if this occurs. If you already experience migraine you should tell your GP this before you start taking hormonal contraceptives.
Some people grind their teeth during the night and find they wake with head pain. If this is the case it is worthwhile seeing a dentist as there are special mouth plates (called occlusal splints) which can reduce the teeth grinding.
- Head injury
Specific head injuries can result in headaches and migraine.
- Muscle tension
Tense muscles in the neck and shoulder areas can cause headaches and may be a premonitory symptom of the migraine starting.
Repeated coughing can lead to a migraine for some people.
These are the most common triggers. If you are prone to getting migraines, it is wise to suspect everything until you have identified or eliminated a particular factor by using your trigger diary.
Dowson, AJ. Migraine and Other Headaches Your Questions Answered. Edinburgh: Churchill Livingstone 2003
Silberstein, SD Lipton, RB Goadsby, PJ Smith, RT. Headache in Primary Care. Oxford: Isis Medical Media,1999
MacGregor, A Understanding Migraine and Other Headaches. Dorset: Family Doctor Publications Ltd, 2005
MacGregor, A Migraine in Women, Revised Edition. London: Martin Dunitz, 2003
Hot Topics in Headache. London: The Migraine Trust 2002