More than 300 million people worldwide — about 6 to 7 percent of men and 15 to 18 percent of women — suffer from migraine headaches, which can last anywhere from a few hours to three days. An estimated 20 million migraine attacks occur every single day.
Despite that, it’s still one of the least understood and poorly treated medical disorders, as they are likely due to a complex interplay of genetic, environmental, and neurological factors that vary from person to person.
Adding to the complexity is that the experiences of those suffering from migraines also vary greatly. Aside from throbbing, searing pain, which may or may not be one-sided, some experience “auras” prior to onset, while others do not. Other symptoms that may or may not be present include nausea, vomiting, fever, chills, sweating, and/or sensitivity to light, sound, and smells.
There are a number of different theories about the cause of migraines, but no one hypothesis can explain the occurrence of migraines in all sufferers. These (sometimes conflicting) theories include:
–Changes in your brain chemical serotonin. When levels drop, blood vessels including those in your brain become swollen and inflamed, which can lead to migraine pain.
-Vascular constriction in your brain; from initial blood vessel constriction and a drop in blood flow, followed by dilation and stretching of blood vessels, which activates pain-signaling neurons.
-Excessive increase of blood flow in your brain. In direct contrast to the preceding theory, other research has found that migraines are not preceded by constriction and decrease in blood flow, but rather by an increase of nearly 300 percent. However, circulation then appears normal, or even slightly reduced, once the attack is in full swing.
-A neurological disorder related to nerve cell activity that sweeps across your brain, causing pain.