Migraine affects 10% of the population and it's believed about 20-30% of the individuals who consult chiropractors.
This is an old Hindu/Buddhist story. 5 blind men examine the same elephant. When asked what is it they give very different answers. What's more their answers confuse the other 4 men. Eventually they take off their blindfolds and realise they had different ends of the same beast not different things in themselves.
Migraine is like the elephant. Headache is the trunk, IBS the tail, restless legs the foot, fatigue, 'stress' and again the symptoms can be diverse and APPEAR unrelated.
Research now reveals that migraine is a brain problem. More specifically the brain has trouble controlling sensations.
There is so much information about migraine these days that it's awfully confusing. Essentially the migraineurs brain is low in serotonin (which has multiple duties - pain and mood control) and other materials ('substrates') such as Vit D and magnesium which nerves use to function.
Because the brain cells can't 'run' themselves properly they can miss fire - the result is disordered brain activity in particular parts of the brain.
So one approach is to provide the brain with these materials. One material that has been researched well is Co enzyme Q10. Another is Vit D although it's a specific type of D and a blood test is required to check it's level. There are also other genetic tests.
The goal here is to make the brain cells more robust and efficient; stronger if you will.
The other side is to identify and reduce triggers or irritants. Some triggers are foods or bright light. Many triggers don't 'work' all the time. It depends on the individuals general neurological robustness. For example you might 'get away' with a red wine today but add some fatigue, lack of sleep (a well known progenitor of migraine) and hey presto - symptoms.
Spinal 'derrangement' adds another 'somatic' component in some individuals. In normal situations a 'stiff' neck might result in nothing more than local discomfort. In a migraineur it can trigger a host of symptoms and effectively end a persons day. Furthermore migraineurs display more scoliosis and postural issues than the norm and we know now that these things are largely brain issues as well.