A severe headache often associated with visual disturbances and nausea or vomiting
- First attack usually occurs by the age of 30; incidence decreases with age
- More common in females
- Sometimes runs in families
- Various things may trigger an attack, including stress, certain foods, too little or too much sleep, and dehydration.
Each year about 1 in 10 people in the UK has a migraine. Migraine is more common in women, and people usually have their first attack before the age of 30. First attacks can occur in children as young as 2 years old (see Migraine in children) but their onset is rare in people over the age of 50. Migraine headaches recur at varying intervals. Some people have attacks several times a month; others have fewer than one a year. Most people find that migraine attacks occur less frequently and become less severe as they get older.
There are two major types of migraine: migraine with aura and migraine without aura. Aura is the term used for a group of symptoms, including visual disturbances, that develops before the onset of the main headache. Migraine with aura accounts for about 1 in 5 of all migraine cases. Some people have attacks of both types of migraine.
What are the causes?
The underlying cause of migraine is not clear but it is thought that it may be due to abnormal activity in the brainstem and changes in the levels of certain neurotransmitters (chemicals in the brain), which then affect other parts of the brain and cause changes in the brain’s blood vessels.
About 8 in 10 people who suffer from migraine have a close relative with the disorder. Stress and depression may be trigger factors, as may the relief of stress, such as relaxing after a difficult day. Other potential triggers include missed meals, lack of or too much sleep, dehydration, and certain foods or drinks, such as cheese, chocolate, and red wine. Many women find that their migraines tend to occur around the time of menstruation.
What are the symptoms?
Migraine headaches, either with or without aura, are sometimes preceded by a group of symptoms that are collectively known as a prodrome. These prodrome symptoms tend to appear about an hour before the main symptoms begin. The prodrome often includes:
Anxiety or mood changes.
Altered sense of taste and smell.
Either an excess or a lack of energy.
People who have a migraine with aura experience a number of further symptoms before the migraine, including:
Visual disturbances, such as blurred vision and bright flashes.
Pins and needles, numbness, or a sensation of weakness on the face or on one side of the body.
The main symptoms, common to both types of migraine, then develop. These symptoms include:
Headache that is severe, throbbing, made worse by movement, and usually felt on one side of the head, over one eye, or around one temple.
Nausea or vomiting.
Abnormal sensitivity to bright light, loud noises, or certain smells.
A migraine may last for anything from a few hours to a few days but eventually clears up. After a migraine, you may feel tired and unable to concentrate.
What might be done?
Your doctor will usually be able to diagnose a migraine from your symptoms. Rarely, tests such as MRI or CT scanning of the brain may be carried out to rule out more serious causes such as a brain tumour.
Once migraine has been diagnosed, your doctor may prescribe drugs that reduce the duration of the attacks, help to treat the symptoms, or prevent further migraines occurring. For example, he or she may prescribe an antimigraine drug, such as a triptan drug that, if taken in the early stages of an attack, will usually prevent the migraine from developing further.
Self-help measures may help to prevent further migraines (see Preventing a migraine). If you experience severe or frequent migraines, your doctor may prescribe a drug such as propranolol (see Beta-blockers) or the anticonvulsants sodium valproate or topiramate to take every day to prevent attacks.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.