What are migraines?

In this section
Key points for people with migraines
Is my headache a migraine?
What causes migraines?
Why me?
Should I see my GP?

If you have been diagnosed as having migraines, you probably already know how much they can affect your life. A migraine attack can be so severe that it stops you getting on with life. An attack can feel like more than just a headache. You may feel odd beforehand, see dots or flashing lights, get pins and needles, or feel queasy or vomit.

The pain from migraines can stop you from going about your daily life.

There's no cure that can stop you getting migraines, but they can be treated. Lots of people cope well with migraines for many years, by taking medicine that stops the symptoms of an attack.

Having migraines doesn't mean something is seriously wrong with your brain. Scientists now think that in people who get migraines, part of their brain is more excitable than normal. Because of this the brain releases high levels of chemicals called neurotransmitters. These make the blood vessels in your brain dilate (get wider) and sometimes get inflamed. This is what causes the pain of migraines.

Key points for people with migraines

• Migraine attacks are severe headaches that last from four to 72 hours.
• You may also have other symptoms, such as feeling sick or being extra-sensitive to sound or light.
• About 1 in 6 people who have migraines get what's called an aura. This can cause temporary problems with your vision or pins and needles or numbness in parts of your body.
• You may be more likely to get a migraine attack if you are tired, hungry or stressed, or eat or drink certain foods.
• Aspirin can help if your pain is not too bad. Or you can try taking a tablet that has aspirin, paracetamol and caffeine for extra relief (two brand names for this are Anadin Extra or Alka XS Go).
• Ibuprofen also works for migraines, but you may need the higher dose, which you can only get on a doctor's prescription.
• Triptans are drugs that work quickly to make you feel better. They can help if you have bad attacks, but they do have side effects. And they don't suit everyone.
• If you get migraine attacks often, talk to your GP about medicine to prevent them. To learn more, see Treatments to prevent migraines.

Is my headache a migraine?

A group of headache specialists called the International Headache Society say that you're having a migraine if your headache lasts between four and 72 hours and you have two of the symptoms listed below:¹

• The pain is on one side of your head (this is called unilateral pain)
• The pain is a throbbing pain
• The pain gets worse when you move
• The pain is moderate or severe. If your pain is moderate, you may be able to keep working, but only half as well as you would normally. If your pain is severe, you usually need to go to bed.

If you have a migraine attack you will also have one or more of the symptoms in this list:¹

• You may feel sick or have an upset stomach or you may actually be sick
• You may be extra-sensitive to light (photophobia)
• You may be extra-sensitive to sounds (phonophobia).

Different types of migraine: with or without auras

About 1 in every 6 people who have migraines also have temporary problems with their vision (usually lasting an hour or less) or feel pins and needles or numbness in parts of their body.¹ You may also find that you cannot move parts of your body normally. These things usually happen before you get a migraine headache, and they are called migraine auras. The aura is a warning of an attack and can be frightening. To learn more, see What causes auras?

How often will I get migraines?

No one can say how often you will get migraine headaches, but the average is slightly more than one a month.¹ Some people get them as often as once a week and others get them much less often.

What causes migraines?

Researchers think that migraines are caused by a problem that makes some cells in your brain more excitable than normal.² It doesn't mean there's anything wrong with your brain. To understand what causes your attacks, you may find it helpful to learn a bit about what your brain does and why it does it. To find out more, see What does your brain do?

Researchers are using new types of scanners to see what happens in the brain when someone has a migraine attack.¹ One of these new types of scanners is a position emission tomography scan, or PET scan for short. This scan picks up the electrical and chemical changes that happen in the brain.

• Researchers believe that there is a pain centre at the base of the brain.
• If you get migraine attacks, you probably have a more sensitive pain centre than other people do. This means that your pain centre is overexcited by things that wouldn't bother someone else, such as bright lights or tiredness.
• The nerve cells in this centre react by telling the blood vessels in certain areas of your brain to open up (dilate). The walls of your blood vessels are slightly elastic, so they can get bigger to let more blood through or get narrower to let less blood through.
• When the blood vessels open up, nerves in the walls of the blood vessels release chemicals (called neurotransmitters) that make the vessels open up even more. These chemicals make the blood vessels inflamed. This is what causes the throbbing pain of a migraine attack.
• Migraine headaches can be so bad that they affect your sympathetic nervous system. This is the part of your nervous system that you have no control over. It gets your body ready to run away or fight any threat that comes along: in this case, a bad headache. In a migraine attack the effect on this part of your nervous system can make you feel sick, vomit, or have diarrhoea.
• When your sympathetic nervous system is affected, the action in your gut may slow down, so it takes longer for the food that you have eaten to leave your stomach. And it also takes longer for any tablets that you have taken to be digested and get into your blood. This is one reason why some treatments for migraine sometimes don't seem to work.
• Your sympathetic nervous system also makes the blood vessels in your skin get narrower, so you look pale. It can also make you more sensitive to what is going on around you, so that lights, noises, or smells are hard to bear.

What causes migraine auras?

Migraine auras seem to be caused by a wave of electrical nerve impulses (excitation) travelling slowly across part of your brain. This is followed by a long period of underactivity in this area.

If you have auras, this underactivity results in reduced action in the part of your body controlled by that section of your brain. The back of your brain, which controls your eyes, is most often affected. This explains why your eyes see only part of what they are looking at. When the areas of your brain that are affected are the ones that control how your body feels, you may feel numb in one part of your body.

What can trigger a migraine attack?

You may find that certain things can set off your migraine attacks. These are called migraine triggers. Different people have different triggers. But it is often hard to work out what the triggers are. There isn't much research on this, but common triggers include:^{3 4}

• Lack of sleep
• Hunger
• Bright lights or loud noises
• Anxiety
• Stress
• Certain foods, such as chocolate and some types of cheese
• Some food additives, such as nitrites, nitrates, and monosodium glutamate (MSG)
• Coffee and some alcoholic beverages, such as red wine
• Hormonal changes in women. For example, some women get migraine attacks when their period starts, when they are on the contraceptive pill or when they are midway through their menstrual cycle
• Changes in the weather, such as a change in barometric pressure
• Some prescribed medications.

Why me?

If you get migraines, you may have inherited the tendency to get these attacks from one of your parents. This means that the tendency to get migraine attacks is in your genes.

Genes are passed from parent to child. They programme how you develop and how your body works. Research shows that certain genes may be linked to migraines. However, genes don't completely explain why some people get migraines.

For some people, there may be something in their environment or something that happens when they are growing up (such as having a certain illness) that causes migraines.⁵ Researchers believe that having migraines with auras is more likely to be caused by genes than migraines without auras are.⁵

Should I see my GP?

You may want to see your GP if:

• Your symptoms don't get better using over-the-counter medicine
• Your migraine attacks have got worse and you get them more often
• You are worried that something other than migraines may be causing your headaches (for example, if you have other symptoms)
• You are not completely free of symptoms between attacks. Tell your doctor if, for example, part of your body feels numb or you have problems with your vision even when you are not having an attack.^{4 6}

Researchers have found that more than half of people who get migraine attacks use only over-the-counter medicines. The researchers suggested that many people with migraine do not see their GP about their headaches because they think that there aren't any treatments that work.⁷ But there are treatments that only your doctor can prescribe that can help. For example, one of the drugs known as triptans may work for you.