Narrator:        This is Science Today. There are two types of headaches - those that are called primary headaches, where the ailment itself is the disorder, such as a migraine. Then there are those called secondary headaches, which are caused by other things happening, such as an infection, a bleed or a tumor. Neurologist Peter Goadsby is a world expert on headaches and is director of the University of California, San Francisco's Headache Clinic.

Goadsby:        The commonest form of disabling or troublesome headache in the Western world is migraine. So, the typical migraine sufferer will have headache triggered by change. Change in sleeping habits - too much or too little. Change in eating habits, skipping meals. Change in the weather, change in levels of stress - too much or too little stress and some particular triggers like alcohol. Now, many migrainers think of that as just normality and it is for them - normality. But in reality, most of that is migraine.

Narrator:        The UC San Francisco Headache Clinic has a broad research program that includes development of new medicines for migraines, as well as brain imaging. For Science Today, I'm Larissa Branin.